Peak level of play (Federer, Nadal, Djokovic & Co.)

[krosero]

Originally Posted by pc1

I mean if a player hits 45 winners and has 15 errors, that would be a 3 to 1 ratio. Another player may hit 15 winners and have only 5 errors but has the same 3 to 1 ratio.

If you do plus-minus the first guy is far better at plus 30 than the second guy at plus 10.

I think ratio may be better.

In a nutshell, I think the Aggressive Margin is better than ratios, and I'll try to explain why as succinctly as I can.

Just like you, I have always suspected that ratios might be better, just from thinking about the problem the way you just laid it out. But when I actually look at the stats I've collected, I find that plus-minus differentials do not put Nadal at a disadvantage. To the contrary, in matches in which he plays far more aggressive players and the match is a close one (we have to assume it's close, to keep things fair), Nadal tends to have better plus-minus differentials than the more aggressive players.

The best example I know is when he beat Verdasco at the 2009 AO. The match was extremely close (Nadal won 193 points, Verdasco 192), so it's a good example of two players who were more or less equal in level of play. Verdasco hit nearly twice as many winners as Nadal did (95 to 52). So it's a perfect example of Nadal facing a much more aggressive player.

But the plus-minus methods do not put him at a disadvantage. Nadal's official winner/error differential was +27, compared to only +19 for Verdasco. So that method treats him fairly: in fact it exaggerates his quality of play, because he didn't win the match by such a large margin. The Aggressive Margin represents the match most accurately: Nadal's AM was 23.9%, Verdasco's 23.6%.

The same occurs in the final that year, between Nadal and Federer (another extremely close match decided by a 1-point edge). Federer usually hits more winners than Nadal. In this match Federer had 71 winners, to Nadal's 50. But Nadal is the one with a better winner/error differential: Federer is at only +7, while Nadal is at +9.

In other words, when Nadal wins matches, it's because he's keeping his unforced errors down extraordinarily low. That's why he can win the winner/error differential contest.

Intuitively, I would have thought that Nadal, like you wrote above, has 15 winners and 5 ue, while his opponent, playing at an equal level, has 45 winners and 15 unforced errors. But the guy with those low numbers will not win that match: he's won 15 points with winners, and 15 points with his opponent's errors. He's got a total of 30 points. Nadal's opponent, on the other hand, has 45 winners + 5 ue from Nadal: a total of 50 points. Nadal's opponent will almost surely beat him, if the ratios advance like this.

What actually happens when different styles clash is that, all things being equal, Nadal will have 15 winners and 15 unforced errors, while Isner will have 50 winners and 50 unforced errors. Either man can win that match.

If the match is of less quality, then Nadal will have 15 winners and 25 errors (-10), while Isner will have 50 winners and 60 errors (-10).

I have many more examples of how Nadal actually looks very good when simple plus-minus methods are used. In the 2006 Wimbledon final, which Nadal lost to Federer in four sets, Nadal had a better winner/error differential than Federer did (+16 compared to +11). That's because something different is going on with the missing category of FORCED errors: but you see what I mean. Plus/minus differentials are often very good for Nadal.

When Nadal lost to Soderling in four sets at RG, again he had a better differential than the man he lost to: +5 compared to +2. And that's an extreme example of clashing styles: Soderling hit almost twice as many winners as Nadal did (61 to 33). Yet Nadal comes out with the better differential.

The Aggressive Margin, again, represents the match accurately: Soderling has 20.7%, Nadal 15.1%.

And in that 2006 Wimbledon final, the AM again is the more accurate method: Federer has 30.5%, Nadal 22.4%.

Soderling, when he upset Federer at RG in 2010, outstripped Roger in winners (49-40). But once again the guy with fewer winners somehow ended up with the better winner/error differential: Soderling's was only +7, while Federer's was +13. Federer kept his UEs down very low (though that was not enough to win him the match).

I do know of one example where a plus/minus method puts Nadal at a disadvantage. When he beat Berdych in their Wimbledon final in 2010 (a straight set match), his winner/error differential was only +8, while Berdych was +10.

So in that case, Nadal's level of play is not represented correctly. But the Aggressive Margin method gets it right: Nadal has 32.2%, Berdych 23.4%.

The odd thing about that example is that we all think of Berdych as having a more aggressive style than Nadal. But Nadal actually hit more winners than Berdych in that match (29-27). And Nadal made more unforced errors than Berdych (21-17). Totally surprising, but that's why Berdych's differentials turned out better than Nadal's.

I thought Nadal really went for his shots in that match. He did it in a controlled way, as always, but he went for them.

It seems that simple winner/error differentials can actually favor the guy who is more patient (or consistent, or cautious), because that guy can keep his unforced errors down extraordinarily low and can therefore come out with a favorable winner/error differential.

The Aggressive Margin method does not have these drawbacks, partly because it considers all the points in a match (forced errors as well as unforced errors).

Thanks for this particular question, PC1, it has helped me to learn a lot more about this method; and it's fun talking about these matches. Like I said, I thought about this ratio problem exactly as you did -- until I checked the differentials I'd gathered over the years.

[krosero]

Originally Posted by abmk

I have a match for nadal with AM greater than 40%. Would like to see if anyone can guess it before I post it .

Hint: a match vs a player within the top 50 ....

What year was it?
10 char

[krosero]

Another great example of clashing styles: 1988 USO final between Wilander and Lendl. Wilander had approximately 35 winners and 35 errors. Lendl was at about 85 winners and 85 unforced errors. The match went down to the wire, 6-4 in the fifth.

I'm taking those stats from memory, but yes, each player's winners and errors were almost exactly equal. Only the totals between the players differed, and by a lot: you can't get a greater contrast in styles than those two men.

Wilander, despite being nowhere near as aggressive as Lendl, is represented accurately in the Aggressive Margins. He had 13.8%, Lendl 12.2%.

Originally Posted by Moose Malloy

I had Becker with 7. I know that's unofficial, but I'm curious what the AM would be in that match. That goes for any of our stats where we calculated UE's(Laver-Ashe etc)
You could just mention that the AM was calculated with unofficial stats when posting some of these(I doubt Laver ever played a match where officials were calculating winners/ue's, may as well use ours just for fun)

If you add those 7 to Becker's 15 df's, his total UE would be 22. Sampras had 7 UE of every kind (all 7 were DF's), per official sources including NBC.

So, if Becker has 22 UE's, Sampras' AM is 44.3%, Becker's 32.1%.

If you give Becker more than 22, Sampras' AM would go down.

If Becker goes down below 22, Sampras' AM would rise. Becker has at least 15 UE's (his df's), so Sampras' ceiling in this match would be 47.2%.

I would be wary of comparing AM's across eras if we go back as far as Laver. (Even comparing against the Sampras era could be problematic). But sure, it's worth doing.

Originally Posted by Moose Malloy

I guess the winner # isn't really necessary in calculating any AM's, just the UE count for both players.

Exactly.

Originally Posted by fed_rulz

Here's a question: are service winners included in the opponents forced error column? IMO, this method would be more accurate if serve-related stats are excluded in calculating the AM.

The AM takes into account every point in the match, so quick answer is yes. The AM is calculated by taking the total number of points that a player won, and subtracting the points that he won through his opponent's unforced errors. The result, mathematically, must be the points that he won aggressively (his Aggressive Points), either through clean winners/aces or by forcing his opponent into errors.

The last step is to take those Aggressive Points and compare them to the same player's Unforced Errors. The final result is the Aggressive Margin.

I can't imagine how this method would be more accurate if service winners are excluded. It MIGHT become more accurate, in that case, if you're looking for levels of play apart from service. But I have doubts about that, because the serve is connected to everything. Not every point in tennis has a forehand, but every point has a serve.

Moose and I have seen matches in which winner/error differentials -- because they only use unforced errors -- give a distorted picture of the match. The loser will come away with a higher winner/error differential, for example. But the loser, in these examples, definitely lost more than 50% of all the points played (we know because we counted). That's how you know that the victor must have pulled ahead in the missing category of forced errors.

And when there is a large difference in the quality of two players' serves -- or a large difference in the quality of their returns -- one player will get a lot more free points by forcing errors on the return. Those errors are not aces, and not outright unreturnable serves, so they don't show up in the typical winner/error stats. But those errors often make the difference.

So I'm not sure what you're trying to isolate by taking out the serve. You might isolate something, but total level of play definitely has to include everything.

[pc1]

Originally Posted by krosero

In a nutshell, I think the Aggressive Margin is better than ratios, and I'll try to explain why as succinctly as I can.

Just like you, I have always suspected that ratios might be better, just from thinking about the problem the way you just laid it out. But when I actually look at the stats I've collected, I find that plus-minus differentials do not put Nadal at a disadvantage. To the contrary, in matches in which he plays far more aggressive players and the match is a close one (we have to assume it's close, to keep things fair), Nadal tends to have better plus-minus differentials than the more aggressive players.

The best example I know is when he beat Verdasco at the 2009 AO. The match was extremely close (Nadal won 193 points, Verdasco 192), so it's a good example of two players who were more or less equal in level of play. Verdasco hit nearly twice as many winners as Nadal did (95 to 52). So it's a perfect example of Nadal facing a much more aggressive player.

But the plus-minus methods do not put him at a disadvantage. Nadal's official winner/error differential was +27, compared to only +19 for Verdasco. So that method treats him fairly: in fact it exaggerates his quality of play, because he didn't win the match by such a large margin. The Aggressive Margin represents the match most accurately: Nadal's AM was 23.9%, Verdasco's 23.6%.

The same occurs in the final that year, between Nadal and Federer (another extremely close match decided by a 1-point edge). Federer usually hits more winners than Nadal. In this match Federer had 71 winners, to Nadal's 50. But Nadal is the one with a better winner/error differential: Federer is at only +7, while Nadal is at +9.

In other words, when Nadal wins matches, it's because he's keeping his unforced errors down extraordinarily low. That's why he can win the winner/error differential contest.

Intuitively, I would have thought that Nadal, like you wrote above, has 15 winners and 5 ue, while his opponent, playing at an equal level, has 45 winners and 15 unforced errors. But the guy with those low numbers will not win that match: he's won 15 points with winners, and 15 points with his opponent's errors. He's got a total of 30 points. Nadal's opponent, on the other hand, has 45 winners + 5 ue from Nadal: a total of 50 points. Nadal's opponent will almost surely beat him, if the ratios advance like this.

What actually happens when different styles clash is that, all things being equal, Nadal will have 15 winners and 15 unforced errors, while Isner will have 50 winners and 50 unforced errors. Either man can win that match.

If the match is of less quality, then Nadal will have 15 winners and 25 errors (-10), while Isner will have 50 winners and 60 errors (-10).

I have many more examples of how Nadal actually looks very good when simple plus-minus methods are used. In the 2006 Wimbledon final, which Nadal lost to Federer in four sets, Nadal had a better winner/error differential than Federer did (+16 compared to +11). That's because something different is going on with the missing category of FORCED errors: but you see what I mean. Plus/minus differentials are often very good for Nadal.

When Nadal lost to Soderling in four sets at RG, again he had a better differential than the man he lost to: +5 compared to +2. And that's an extreme example of clashing styles: Soderling hit almost twice as many winners as Nadal did (61 to 33). Yet Nadal comes out with the better differential.

The Aggressive Margin, again, represents the match accurately: Soderling has 20.7%, Nadal 15.1%.

And in that 2006 Wimbledon final, the AM again is the more accurate method: Federer has 30.5%, Nadal 22.4%.

Soderling, when he upset Federer at RG in 2010, outstripped Roger in winners (49-40). But once again the guy with fewer winners somehow ended up with the better winner/error differential: Soderling's was only +7, while Federer's was +13. Federer kept his UEs down very low (though that was not enough to win him the match).

I do know of one example where a plus/minus method puts Nadal at a disadvantage. When he beat Berdych in their Wimbledon final in 2010 (a straight set match), his winner/error differential was only +8, while Berdych was +10.

So in that case, Nadal's level of play is not represented correctly. But the Aggressive Margin method gets it right: Nadal has 32.2%, Berdych 23.4%.

The odd thing about that example is that we all think of Berdych as having a more aggressive style than Nadal. But Nadal actually hit more winners than Berdych in that match (29-27). And Nadal made more unforced errors than Berdych (21-17). Totally surprising, but that's why Berdych's differentials turned out better than Nadal's.

I thought Nadal really went for his shots in that match. He did it in a controlled way, as always, but he went for them.

It seems that simple winner/error differentials can actually favor the guy who is more patient (or consistent, or cautious), because that guy can keep his unforced errors down extraordinarily low and can therefore come out with a favorable winner/error differential.

The Aggressive Margin method does not have these drawbacks, partly because it considers all the points in a match (forced errors as well as unforced errors).

Thanks for this particular question, PC1, it has helped me to learn a lot more about this method; and it's fun talking about these matches. Like I said, I thought about this ratio problem exactly as you did -- until I checked the differentials I'd gathered over the years.

You've done the studies so I believe you.

Originally Posted by krosero

Another great example of clashing styles: 1988 USO final between Wilander and Lendl. Wilander had approximately 35 winners and 35 errors. Lendl was at about 85 winners and 85 unforced errors. The match went down to the wire, 6-4 in the fifth.

I'm taking those stats from memory, but yes, each player's winners and errors were almost exactly equal. Only the totals between the players differed, and by a lot: you can't get a greater contrast in styles than those two men.

Wilander, despite being nowhere near as aggressive as Lendl, is represented accurately in the Aggressive Margins. He had 13.8%, Lendl 12.2%.

If you add those 7 to Becker's 15 df's, his total UE would be 22. Sampras had 7 UE of every kind (all 7 were DF's), per official sources including NBC.

So, if Becker has 22 UE's, Sampras' AM is 44.3%, Becker's 32.1%.

If you give Becker more than 22, Sampras' AM would go down.

If Becker goes down below 22, Sampras' AM would rise. Becker has at least 15 UE's (his df's), so Sampras' ceiling in this match would be 47.2%.

I would be wary of comparing AM's across eras if we go back as far as Laver. (Even comparing against the Sampras era could be problematic). But sure, it's worth doing.

Exactly.

The AM takes into account every point in the match, so quick answer is yes. The AM is calculated by taking the total number of points that a player won, and subtracting the points that he won through his opponent's unforced errors. The result, mathematically, must be the points that he won aggressively (his Aggressive Points), either through clean winners/aces or by forcing his opponent into errors.

The last step is to take those Aggressive Points and compare them to the same player's Unforced Errors. The final result is the Aggressive Margin.

I can't imagine how this method would be more accurate if service winners are excluded. It MIGHT become more accurate, in that case, if you're looking for levels of play apart from service. But I have doubts about that, because the serve is connected to everything. Not every point in tennis has a forehand, but every point has a serve.

Moose and I have seen matches in which winner/error differentials -- because they only use unforced errors -- give a distorted picture of the match. The loser will come away with a higher winner/error differential, for example. But the loser, in these examples, definitely lost more than 50% of all the points played (we know because we counted). That's how you know that the victor must have pulled ahead in the missing category of forced errors.

And when there is a large difference in the quality of two players' serves -- or a large difference in the quality of their returns -- one player will get a lot more free points by forcing errors on the return. Those errors are not aces, and not outright unreturnable serves, so they don't show up in the typical winner/error stats. But those errors often make the difference.

So I'm not sure what you're trying to isolate by taking out the serve. You might isolate something, but total level of play definitely has to include everything.

Interesting how in the 1988 US Open Lendl was deemed to be more aggressive but I understand that's a part of his more powerful stroking style. We often (not me by the way)relate aggressive play to rushes to the net. If I recall Wilander rushed the net far more often. Another question does occur to me, net rushes often forces passing shots errors, can we statistically take this into account?

[krosero]

Originally Posted by abmk

what makes you think that federer had his peak level b/w 2008 and 2012 ?

that's just from the list of matches krosero has. it isn't a comprehensive list by any means ...

just that he probably has more stats of matches in 2008-12

I do, I have about twice as many in those years.

AM's calculated:

2012 – 42
2011 – 32
2010 – 18
2009 – 22
2008 – 26
2007 – 22
2006 – 14
2005 – 18
2004 – 8
2003 – 6

2003-07 = 74
2008-12 = 140

(Gotta love the way Excel makes these counts so easy.)

[krosero]

Originally Posted by pc1

Interesting how in the 1988 US Open Lendl was deemed to be more aggressive but I understand that's a part of his more powerful stroking style. We often (not me by the way)relate aggressive play to rushes to the net. If I recall Wilander rushed the net far more often. Another question does occur to me, net rushes often forces passing shots errors, can we statistically take this into account?

You know, that's my favorite match, yet in all this talk about aggressive play I had actually forgotten about Wilander's net rushes. We typically think of aggression as hitting winners, but in past eras "aggressive" meant rushing the net! Absolutely right.

Wilander had, I think, 131 approaches, Lendl 77. Lendl was aggressive, too, by that measure -- more than most players today. But Wilander was twice as willing to come forward.

That was part of the reason that Lendl hit so many more winners: Wilander forced him to hit a ton of passing shots.

You ask if we can take passing shot errors into account. Rushing the net and forcing your opponent into errors is certainly an aggressive play. The AM, strictly speaking, does not count net rushes, so it doesn't award players just for rushing the net. But the statisticians scoring the match, when they see a player make an error while attempting a passing shot, will score the error as forced. So when you calculate the Aggressive Margin, his opponent will be rewarded for forcing all those errors.

For AM purposes it doesn't matter whether a player was aggressive by rushing the net or by doing something else, like hitting a powerful forehand from the opposite baseline. As long as the resulting error is scored as forced, the player is rewarded and will generate a higher Aggressive Margin.

[abmk]

Here's one more way of looking at the AM :

I'll derive it from the actual formula :

AM = (winners+errors forced from opponent-unforced errors)/total no of points



now we know , errors forced from opponent = total points won - winners - unforced errors of opponent

putting that in :

AM = (winners+(total points won-winners-unforced errors of opponent)-unforced errors)/total no of points

i.e = AM = (total points won -unforced errors of opponent - unforced errors)/total no of points

i.e. AM = (total points won - sum of unforced errors)/total no of points

=> the player with more no of points won *always* has the higher aggressive margin

[krosero]

Originally Posted by RoddickAce

I think your analysis is quite interesting, but I disagree with the bolded statement. It also depends on what you define as peak. Are we referring to a period of time? ie. 2005-2006 for Federer. Or are we referring to peak levels in certain matches? If you are referring to peak level in certain matches, then that is fine, but players like Berdych, Tsonga and Del Potro will have very high margins for certain matches. If we are drawing a conclusion from the sample about a period of time, then there are some points to consider (see the reasons below).

To clarify, I don't think there is anything wrong with biasing towards more aggressive players since you are effectively trying to measure how aggressive a player relative to his/her errors.

Reasons for bias towards aggressive players:

1) Aggressive players play high risk high reward tennis, over the wide spread of matches played throughout one's career, they are more likely to have wins with a high margin of aggressively won points over unforced errors, than their defensive counterparts. This can cause skewed results. For example, let's say Isner and Nadal play 150 matches against the field during the defined "peak period" (150 matches is roughly 2-2.5 years).

• Isner -Being a risky player, Isner always has a high winner/forced error, high unforced ratio. Over his 150 matches, his aggressive margin is 10%, because of his high unforced error count. However, he gets on fire 10 of the 150 (6.67%) matches he played, and has a high margin of 50% for his top 10 scores, supposedly representing his peak period.

• Nadal -Being a defensive player, Nadal has a lower winner, lower unforced ratio. Over his 150 matches, his aggressive margin is 25%. Because of his steady play, this 25% held true for each of his 200 matches. Thus, his top 10 matches also average 25%, which is 1/2 of what Isner achieved in his top 10 matches.

This clearly does award players that "we normally think of as "an aggressive player."

To reduce this bias, perhaps one can define a peak period, say all matches in 2005 and 2006, and then select a random sample of matches to calculate the aggressive margin, rather than selecting the top aggressive margins over a large amount of years.

2) Also, using a direct calculation of % points won aggressively subtracting the % points lost due to unforced errors will be advantageous for the aggressive player.

ie: In a match, Isner won 50% of points aggressively, but lost 30% of points due to unforced errors. The aggressive margin is 20%. The RATIO is 50/30 = 1.67 times more aggressively won points than errors.

Nadal won 15% of points aggressively, but lost 2% of points due to unforced errors. The aggressive margin is 13%. The RATIO is 7.5 times more aggressively won points than errors.

Which statistic is actually more impressive in terms of "balancing aggressive shots and errors" as you said you were trying to find out from the stats?

Some good points here. I think already, in my post to PC1, I addressed the arguments you make in your #2 section, concerning ratios vs margins. But I'll address your arguments specifically.

1) - you're talking about how high-risk players can get "hot" every once in a while and produce levels of play that more consistent players rarely, if ever, reach. That's an excellent point, and it certainly applies to players like Tsonga, Berdych, Isner.

However, it doesn't apply to Federer. No one, Nadal included, is more consistent than Federer. How many times is Federer upset in the early rounds of a tournament? Not often -- and it certainly has happened more frequently to Nadal, particularly in Slams. Federer may be high-risk if you look at his style in a certain way -- compared to Nadal, or Djokovic -- but his style is very far from hit-or-miss. And he doesn't have the temperamental psychology that makes some other players perform like a tennis god one day and then crap out the UE's in the next round.

When it comes to someone like Tsonga, no one doubts what you're saying. Tsonga's top AM's may exceed 40% or even 50% when his career is over, and those top figures might beat Nadal's top figures. But for average level of play, Nadal has Tsonga beaten hands down.

And you can see that illustrated very simply just by looking at their title count -- and the basic progress of their matches on tour. It's plain that Tsonga has more up-and-down days.

I just don't think the Nadal/Federer comparison works the same way. Federer has higher AM's. But it's not because he's a hot-and-cold player while Nadal is consistent. No one has been more consistent from day to day than Federer.

And you can see that in Federer's AM's. It's not just one or two AM's, like Tosnga produced on hot days, that are superior to Nadal's. Federer has several AM's over 40% (ABMK says he has Nadal at over 40% in one match); and Federer has several more in the high 30s, on my list, before Nadal's highest AM appears.

2) -- Here you're talking about how winner/error margins contrast with winner/error ratios. This was the question raised by PC1. He suggested that great, consistent defenders like Nadal might be better represented by ratios. I posted, in reply, several instances where Nadal comes out ahead of his opponent, if margins are used.

In short, Nadal does not win his matches by making 15 winners and 5 ue while his opponent (let's say it's Isner) makes 45 winners and 15 ue. Nadal can't win that match, because he's won only 30 points in total, while Isner has won 50. They might have same 3-to-1 ratio of winners/ue, but that's entirely inaccurate, given that Isner has probably won that match quickly in straight sets.

Your numbers are similar. You've got Isner already winning 50% of the points through his own aggressive plays. Plus he's taken 2% of the points through Nadal's unforced errors. So Isner has won 52% of the points in the match, at least; he has out-played Nadal, even if Nadal, as he sometimes does, steals the victory through mental or physical stamina when he has only won 48% of the points in the match.

Now, I'm not just being picky about the numbers you've chosen. I'm talking about which method is superior, as a way to measure quality of play. I'm saying, Isner has a higher Aggressive Margin than Nadal in this example, but that's entirely accurate, since Isner is out-playing Nadal. I'm also saying that, in your example, Nadal has the much higher RATIO of winners to errors: but that's entirely inaccurate as a measure of who is playing better. The ratio makes it seem that Nadal is playing entire levels above Isner, when in fact Rafa has been out-played in points won and will probably lose the match.

Your numbers don't quite add up to 100%, so I'll change them just a little.

Let's say Isner wins 48% of the points through his aggressive plays. He's also got 2% from Rafa's unforced errors. He's got 50% of the points. Nadal has won 15% of the points aggressively, and 35% from Isner's unforced errors.

Each man is tied in total points won, so we have a fair playing field to decide which method is better.

Isner's winner/error ratio is 48/35, or 1.37. Nadal's ratio is 15/2, or 7.50. Completely inaccurate. Nadal looks like he's killing Isner, when in fact they're neck-and-neck.

Isner's Aggressive Margin is 48% - 35%, or 13%. Nadal's AM is 15% - 2%, or 13%. That's a precise representation of the distance between the two men.

I had never noticed it before, but the Aggressive Margin will always tell you accurately which player won the most points. It's tied in mathematically to the breakdown of Total Points Won. I tried it in Excel today, punching in various numbers for Unforced Errors to see if I could get Isner and Nadal to produce the numbers that you gave them. It turns out that you can put in any numbers you want, for the Unforced Errors; it doesn't matter; if Nadal and Isner have won the same number of points, their Aggressive Margins will be equal to one another. If Isner wins 90 points and Nadal 89, Isner's AM will be slightly higher than Nadal's. It has to work out that way mathematically.

Try it out in Excel. You can give Isner 145 unforced errors, and Nadal only 2; or you can give them both 40 unforced errors; the particular figures don't matter. The player's AM's will always reflect the actual margin of victory in Total Points Won.

What the exact AM's will be, of course, is totally dependent on how many UE's the players make. The actual UE figures determine the quality of the AM's.

But the AM's always accurately represent who won the most points, and by how much. I'm not sure any method can hope to be more fair than that.

Because I have all this data in Excel, I can easily sort by different criteria and compare different methods. I took all my data today and sorted it by ratios, rather than by Aggressive Margins. The ratios end up distorting a lot; but I'll put that it another post.

[abmk]

Originally Posted by krosero

What year was it?
10 char

2008 .........

[krosero]

Originally Posted by abmk

=> the player with more no of points won *always* has the higher aggressive margin

Ha! Another cross-posting with mine. Excellent.

Clearly we're all on the same page.

[abmk]

Originally Posted by krosero

But the AM's always accurately represent who won the most points, and by how much. I'm not sure any method can hope to be more fair than that.

.

krosero,

you can derive that from the formula for AM :

AM = (total points won - sum of unforced errors)/total no of points

see post #27

[abmk]

Originally Posted by krosero

Ha! Another cross-posting with mine. Excellent.

Clearly we're all on the same page.

indeed

[krosero]

Originally Posted by abmk

2008 .........

Almagro at RG?

[abmk]

Originally Posted by krosero

Almagro at RG?

Assuming the UE counts on RG site are fine, no ..

his AM was 30.8% in that match ..

[TheFifthSet]

i have a feeling the federer-tomic match at last years AO would register rather high up there.

[abmk]

Originally Posted by TheFifthSet

i have a feeling the federer-tomic match at last years AO would register rather high up there.

umm, not in absolute terms as the speed of AO ( these days even more so ) doesn't favour higher AMs, ;I don't think it'd be go above 30% in any case ...

at the AO, probably might be one of the highest though ...

let me check ...

[abmk]

Originally Posted by krosero

Thanks all for the comments, will post replies as a I have time.

Just a few quick replies now.

Yes those official stats are messed up, but fortunately they don't have an impact on the AM. As long as the unforced errors can be trusted -- and they do look ok -- then the remaining points can be regarded as either forcing points or as clean winners, without worrying about how many exactly were clean winners. That's the problem with the official stats: the figures that they have for Winners are actually the number of points that each player won, in total, on serve (ie, Federer won 31 points on his own serve, Nadal won 46 on his own).

In 2007 the RG site also had a problem counting Winners, and I don't know how the Winners were calculated that year. Fortunately, again, it doesn't have an impact on the AM, so long as the Unforced Errors look reliable, which they do.

the unforced errors column *may* be ok ... I counted 17 UEs for federer ( they had 12 ) and 4 UEs for nadal ( they had 3 ) in the first set ... Maybe I was a bit harsher in evaluating UEs, whereas the statistician was a bit more lenient or a combination of the 2 ....

Originally Posted by krosero

The official Wimbledon stats in '99 have Unforced Errors that are completely unreliable. Those figures look like the total number of errors of every kind, forced and unforced. They've got Sampras at 51 unforced errors. NBC put Sampras at only 22, which looks right. Unfortunately I don't know the UE count that NBC had for Agassi, so AM's can't be calculated.

Do you have any idea what the UE counts were for the Stich match?

Or the UE count for Becker in the '95 Wimby final?

I don't have the UE stats for either of the matches.

yeah, I did see the stats for the wimbledon 99 final .. looks like they combined forced and unforced errors as 'unforced errors'.

do you have the UE counts for the krajicek-sampras match in 96 ? I saw the huge boxscore on the site, some really really detailed stats, but sadly can't get the total UE count from there !

[RoddickAce]

Originally Posted by krosero

Some good points here. I think already, in my post to PC1, I addressed the arguments you make in your #2 section, concerning ratios vs margins. But I'll address your arguments specifically.

1) - you're talking about how high-risk players can get "hot" every once in a while and produce levels of play that more consistent players rarely, if ever, reach. That's an excellent point, and it certainly applies to players like Tsonga, Berdych, Isner.

However, it doesn't apply to Federer. No one, Nadal included, is more consistent than Federer. How many times is Federer upset in the early rounds of a tournament? Not often -- and it certainly has happened more frequently to Nadal, particularly in Slams. Federer may be high-risk if you look at his style in a certain way -- compared to Nadal, or Djokovic -- but his style is very far from hit-or-miss. And he doesn't have the temperamental psychology that makes some other players perform like a tennis god one day and then crap out the UE's in the next round.

When it comes to someone like Tsonga, no one doubts what you're saying. Tsonga's top AM's may exceed 40% or even 50% when his career is over, and those top figures might beat Nadal's top figures. But for average level of play, Nadal has Tsonga beaten hands down.

And you can see that illustrated very simply just by looking at their title count -- and the basic progress of their matches on tour. It's plain that Tsonga has more up-and-down days.

I just don't think the Nadal/Federer comparison works the same way. Federer has higher AM's. But it's not because he's a hot-and-cold player while Nadal is consistent. No one has been more consistent from day to day than Federer.

And you can see that in Federer's AM's. It's not just one or two AM's, like Tosnga produced on hot days, that are superior to Nadal's. Federer has several AM's over 40% (ABMK says he has Nadal at over 40% in one match); and Federer has several more in the high 30s, on my list, before Nadal's highest AM appears.

2) -- Here you're talking about how winner/error margins contrast with winner/error ratios. This was the question raised by PC1. He suggested that great, consistent defenders like Nadal might be better represented by ratios. I posted, in reply, several instances where Nadal comes out ahead of his opponent, if margins are used.

In short, Nadal does not win his matches by making 15 winners and 5 ue while his opponent (let's say it's Isner) makes 45 winners and 15 ue. Nadal can't win that match, because he's won only 30 points in total, while Isner has won 50. They might have same 3-to-1 ratio of winners/ue, but that's entirely inaccurate, given that Isner has probably won that match quickly in straight sets.

Your numbers are similar. You've got Isner already winning 50% of the points through his own aggressive plays. Plus he's taken 2% of the points through Nadal's unforced errors. So Isner has won 52% of the points in the match, at least; he has out-played Nadal, even if Nadal, as he sometimes does, steals the victory through mental or physical stamina when he has only won 48% of the points in the match.

Now, I'm not just being picky about the numbers you've chosen. I'm talking about which method is superior, as a way to measure quality of play. I'm saying, Isner has a higher Aggressive Margin than Nadal in this example, but that's entirely accurate, since Isner is out-playing Nadal. I'm also saying that, in your example, Nadal has the much higher RATIO of winners to errors: but that's entirely inaccurate as a measure of who is playing better. The ratio makes it seem that Nadal is playing entire levels above Isner, when in fact Rafa has been out-played in points won and will probably lose the match.

Your numbers don't quite add up to 100%, so I'll change them just a little.

Let's say Isner wins 48% of the points through his aggressive plays. He's also got 2% from Rafa's unforced errors. He's got 50% of the points. Nadal has won 15% of the points aggressively, and 35% from Isner's unforced errors.

Each man is tied in total points won, so we have a fair playing field to decide which method is better.

Isner's winner/error ratio is 48/35, or 1.37. Nadal's ratio is 15/2, or 7.50. Completely inaccurate. Nadal looks like he's killing Isner, when in fact they're neck-and-neck.

Isner's Aggressive Margin is 48% - 35%, or 13%. Nadal's AM is 15% - 2%, or 13%. That's a precise representation of the distance between the two men.

I had never noticed it before, but the Aggressive Margin will always tell you accurately which player won the most points. It's tied in mathematically to the breakdown of Total Points Won. I tried it in Excel today, punching in various numbers for Unforced Errors to see if I could get Isner and Nadal to produce the numbers that you gave them. It turns out that you can put in any numbers you want, for the Unforced Errors; it doesn't matter; if Nadal and Isner have won the same number of points, their Aggressive Margins will be equal to one another. If Isner wins 90 points and Nadal 89, Isner's AM will be slightly higher than Nadal's. It has to work out that way mathematically.

Try it out in Excel. You can give Isner 145 unforced errors, and Nadal only 2; or you can give them both 40 unforced errors; the particular figures don't matter. The player's AM's will always reflect the actual margin of victory in Total Points Won.

What the exact AM's will be, of course, is totally dependent on how many UE's the players make. The actual UE figures determine the quality of the AM's.

But the AM's always accurately represent who won the most points, and by how much. I'm not sure any method can hope to be more fair than that.

Because I have all this data in Excel, I can easily sort by different criteria and compare different methods. I took all my data today and sorted it by ratios, rather than by Aggressive Margins. The ratios end up distorting a lot; but I'll put that it another post.

Ah, I see thanks for the clarification! For point 1, I was under the impression that this was just used to measure all players across the board, but I guess you also took into consideration the consistency of Fed/Nadal specifically.

And for point two I thought you meant % of aggressive points won as in aggressive points divided by total points won by the specific player, rather than divided by the total points in the match, so that's why there's that confusion there too (ie. not adding up to 100% for Isner and Nadal's points won).

But ya, thanks for going through the analysis and answering my post! Too often my posts on this forum get overshadowed because the OP is too busy defending against troll posts LOL!

[pc1]

Originally Posted by krosero

You know, that's my favorite match, yet in all this talk about aggressive play I had actually forgotten about Wilander's net rushes. We typically think of aggression as hitting winners, but in past eras "aggressive" meant rushing the net! Absolutely right.

Wilander had, I think, 131 approaches, Lendl 77. Lendl was aggressive, too, by that measure -- more than most players today. But Wilander was twice as willing to come forward.

That was part of the reason that Lendl hit so many more winners: Wilander forced him to hit a ton of passing shots.

You ask if we can take passing shot errors into account. Rushing the net and forcing your opponent into errors is certainly an aggressive play. The AM, strictly speaking, does not count net rushes, so it doesn't award players just for rushing the net. But the statisticians scoring the match, when they see a player make an error while attempting a passing shot, will score the error as forced. So when you calculate the Aggressive Margin, his opponent will be rewarded for forcing all those errors.

For AM purposes it doesn't matter whether a player was aggressive by rushing the net or by doing something else, like hitting a powerful forehand from the opposite baseline. As long as the resulting error is scored as forced, the player is rewarded and will generate a higher Aggressive Margin.

It's funny, that could be my favorite match too along with the 1984 Connors/McEnroe US Open semi and a couple of others. I play the 1988 US Open final as background video often on the TV or computer monitor when I'm doing some paperwork.

[TheFifthSet]

Originally Posted by abmk

umm, not in absolute terms as the speed of AO ( these days even more so ) doesn't favour higher AMs, ;I don't think it'd be go above 30% in any case ...

at the AO, probably might be one of the highest though ...

let me check ...

ok, thanks! yeah you're most likely right, i just remember fed being on fire in that match, shooting winners left and right.