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

[krosero]

Originally Posted by abmk

in the final, avg serve speeds :

federer :

1st set : 1st serve : 115 mph, 2nd serve : 96 mph
2nd set: 1st serve : 116 mph, 2nd serve : 101 mph
3rd set : 1st serve : 117 mph, 2nd serve : 100 mph
4th set : 1st serve : 116 mph, 2nd serve: 99 mph

only in the first set, speed was less, so I don't think it had to do with the roof ....

ESPN reported that Federer's average 1st serve went from 120 mph before the roof closed to 125 after. That does not square at all, obviously, with the stats you've got here, from the official Wimbledon site. That site has Federer's fastest serve at 130, but his average was not as high as 120-125.

Different radar guns used?

[abmk]

Originally Posted by krosero

Semifinal
Djokovic got back 57 of Federer’s 101 good serves: 56.4%
Federer got back __ of Djokovic’s 113 good serves: __%

(those stats are from Wimbledon.com and the New York Times tennis blog)

Final
Murray got back 99 of Federer’s 128 good serves: 77.3%
Federer got back 107 of Murray’s 156 good serves: 68.6%

I got stats for the final by using a graphic that was shown in the fourth set. At 2-all, 15-love, right after Murray forces a BH return error, the graphic had Murray with 43 unreturned serves and Federer with 25. I counted to the end – including aces in my count, which I think is the way this is done though I'm not absolutely certain – and finished with Murray at 49 and Federer 29.

The graphic makes it look like Murray was doing nearly twice as well as Federer in serving unreturned serves. That's because it's a simple count of how many serves were unreturned; it does not take into account the fact that Murray served a lot more points in the match than Federer did. When you convert the counts to the percentages above, there was not much of a difference between the two players.

ABMK, even though Federer had more mph on his serves in the semifinal, compared to what he served at Murray, I think these numbers support your argument that Murray returned better than Djokovic (btw I'll have more extensive replies to your posts later).

Federer's second serve was really humming in the semifinal, so if anyone counts the return errors in this match it would be useful to know how many of his second serves went unreturned. If a LOT of Djokovic's return errors occurred on second serve then we might have to give more credit to Federer for making Djokovic's returning look worse than Murray's.

Anyone have those numbers that I'm missing for Federer in the semi?

At 2-5 in the 4th, with djoker serving @ at 15 all, they showed this stat :

returns % in play :

federer : 68%
djokovic : 57%

djokovic put in 5 more serves after that, of which federer put 3 back into play

djokovic served a total of 115 points, including 2 DFs, so that means federer at that time they showed the stat had returned ( 115-2-5 = 108 )

108*68/100 ~ 73 of those ..

so in the end, 76 out of 113 ~ 67.3%

.....

including aces is the right way to go about it ..

don't have a count of the no of errors forced on the 2nd serve by federer in the semi ...

[krosero]

Originally Posted by abmk

I did the UE stats for this as well,

wimbledon.org has UEs by set :

federer : 2,3,4,1 - total of 10
djokovic : 5,3,9,5 - total of 22


I have significantly different :

federer : 4,4,9,1 - total of 18
djokovic : 6,3,11,7 - total of 27

which brings their AMs to :

federer : 31.95%
djokovic : 26.4%


funnily enough, I have 4 UEs on the return for fed,7 for djoker
wimbledon.org has 5 for fed and 8 for djoker

so I don't know how lenient the statistician was on strokes apart from the return

My initial impression was justified, there were more unforced errors than what is on the site and difference is non-trivial ..

If by any chance, you are planning to watch this, can you please keep track of the UEs and see how many you end up with ?

Yes if I watch it again I'll do an UE count.

Your method was probably less lenient than the official statistician's.

That's why for comparing the semi with the final it would probably be best to stick to the official UE's, because presumably the same method was used for both matches.

By the official numbers, the final still looks like less quality than the semi (though not by much).

Originally Posted by corners

I re-watched this match a couple days ago and had the same reaction I had the first time I watched and saw the very low UE count flash on screen: What!?

BTW, I didn't score it because I don't know how. Can anyone suggest an authoritative guide to differentiating UE, winners and forced errors?

Here are some links.

An interview with Leo Levin:
http://tt.tennis-warehouse.com/showthread.php?t=133106
and here: http://www.usatoday.com/sports/tenni...d-errors_N.htm

[krosero]

Originally Posted by abmk

At 2-5 in the 4th, with djoker serving @ at 15 all, they showed this stat :

returns % in play :

federer : 68%
djokovic : 57%

djokovic put in 5 more serves after that, of which federer put 3 back into play

djokovic served a total of 115 points, including 2 DFs, so that means federer at that time they showed the stat had returned ( 115-2-5 = 108 )

108*68/100 ~ 73 of those ..

so in the end, 76 out of 113 ~ 67.3%

.....

including aces is the right way to go about it ..

don't have a count of the no of errors forced on the 2nd serve by federer in the semi ...

thanks for that, I've edited my post

[corners]

Originally Posted by krosero

By the official numbers, the final still looks like less quality than the semi (though not by much).

From a subjective standpoint I thought Fed played the last two sets of the final at a much higher level than the semi. I wonder if the stats would back me up. Maybe I'll see if they do, with ...

Here are some links.

An interview with Leo Levin:
http://tt.tennis-warehouse.com/showthread.php?t=133106
and here: http://www.usatoday.com/sports/tenni...d-errors_N.htm

Thanks Krosero. The piece with the Levin, McEnroe, Roddick, Fed quotes is pretty great. I like how Fed scoffs: "...the statistics guys have no clue what an unforced error is," he said. "I had only about half that."

[abmk]

Originally Posted by corners

I re-watched this match a couple days ago and had the same reaction I had the first time I watched and saw the very low UE count flash on screen: What!?

BTW, I didn't score it because I don't know how. Can anyone suggest an authoritative guide to differentiating UE, winners and forced errors?

well no authorative guide, but just some pointers :

for winners , its mostly simple :

clean winners : on which opponent did not get a racquet on
judgement winners : on which the opponent got a very very slight touch on

the judgement b/w what error is forced and unforced is more complicated and disagreements/doubts can occur :

if the error occurred due to pace, spin or angle of the opponent's shot or low bounce or ball dipping at the net or hit at great depth at the baseline or the player was on the run or stretching or if the opponent was at the net near to cutting off the easy angles, I'd say that error was forced

again, basically all cases in which the opponent forced the error in some way

otherwise the error should be classified as unforced ... ( DFs included )

[abmk]

Originally Posted by corners

From a subjective standpoint I thought Fed played the last two sets of the final at a much higher level than the semi. I wonder if the stats would back me up. Maybe I'll see if they do, with ...

yeah, I think so too ..... maybe not much higher, but significantly higher ....this was *with* murray still getting back so many returns into play ...

the last 2 sets were probably the best he's played on grass since the haas semi in 2009 ...

[abmk]

Originally Posted by krosero

Yes if I watch it again I'll do an UE count.

Your method was probably less lenient than the official statistician's.

That's why for comparing the semi with the final it would probably be best to stick to the official UE's, because presumably the same method was used for both matches.

By the official numbers, the final still looks like less quality than the semi (though not by much).

well, that's what's puzzling me , I don't think I was that strict in counting UEs tbh ... many of those were simple unforced errors, there was no doubt that they were in fact unforced, for example, if you remember the epic rally on one BP on djoker's serve in the 3rd set, there was some brilliant hitting and defense in that rally, but ended with a wild forehand miss from federer when he went for a bit too much trying to hit a FH DTL ...

the stats in the final look alright to me .....Was it the same statistician who did both the matches ?

[krosero]

Originally Posted by abmk

federer did obviously find it easier vs murray's 2nd serve, but first serve ? I think murray's was better ... not that much of a difference in federer's returning in the semis and finals, but I think he was a bit better in the finals than in the semis

Now that we have the exact return stats, I'll say that at least per the numbers, Federer's returning looks better in the semis. His rate of "Returns In" was 67.3% against Djokovic and 68.6% against Murray, not a great difference.

The great difference IMO is that Djokovic was serving better than Murray. Novak's average first serve was 120 mph, just 1 mph less than Murray's. But the average second serve was a significant difference: Djok 95 mph and Murray 88 mph.

Murray's always had a bit of a problem on second serves; Federer was swiping at them. (Novak's also taken advantage of Murray's second serve, eg, 2012 AO).

So was Federer's quality of return really higher in the final, or was it made to seem that way by how effectively he could attack Murray's second serve?

Originally Posted by abmk

well, IMO, the roof being closed did play a part in those stats.

at wimbledon :

I think federer served exceptionally brilliantly in the semis, but he did return better in the finals ..

murray in the finals also returned quite a bit better than djoker did in the semis ...

the matches were closer in quality than the respective AMs seem to suggest ...

differences being the roof and the better quality of returning resulting in more rallies and as a result more UEs in the final

This part I bolded: you've rewatched the semi since you wrote this, so I don't know if this is still your argument about the UE's.

But it's still an interesting question whether better returning can produce higher UE's and thus lower AM's.

In these matches I don't think the argument works. I had forgotten how many times Federer came to net in the final: he had 68 approaches, nearly three times what he had against Djokovic. That, by itself, would not leave much room for baseline rallies in the final.

And now that we got the missing numbers for these matches, we can actually calculate how many baseline rallies there were. Just exclude all the aces, double-faults, net approaches and return errors, and you should have the # of baseline rallies almost exactly (it's not completely exact because we don't know if there were any points in which both players made approaches: but those points are rare).

So this is what I got:

86 baseline rallies in Fed/Djokovic: 40% of all points played.
99 baseline rallies in Fed/Murray: 34% of all points played.

So Fed/Murray may or may not have had better quality of returning than Fed/Djok, but even if it did, the result was not a greater number of baseline rallies leading to more UE's. Fed/Djokovic was the match that was played more from the baseline: and yet it's the match with lower UE's.

The returning in the final might have produced more baseline rallies, but Federer's charging the net essentially prevented that.

[corners]

Originally Posted by abmk

the last 2 sets were probably the best he's played on grass since the haas semi in 2009 ...

Yeah, you're probably right.

[abmk]

Originally Posted by krosero

Now that we have the exact return stats, I'll say that at least per the numbers, Federer's returning looks better in the semis. His rate of "Returns In" was 67.3% against Djokovic and 68.6% against Murray, not a great difference.

The great difference IMO is that Djokovic was serving better than Murray. Novak's average first serve was 120 mph, just 1 mph less than Murray's. But the average second serve was a significant difference: Djok 95 mph and Murray 88 mph.

Murray's always had a bit of a problem on second serves; Federer was swiping at them. (Novak's also taken advantage of Murray's second serve, eg, 2012 AO).

So was Federer's quality of return really higher in the final, or was it made to seem that way by how effectively he could attack Murray's second serve?

well , the first statement I made after re-watching was that I think federer returned equally well in both

federer could and did attack murray's 2nd serve more, but in doing so, he missed quite a few more 2nd serves than he did vs djoker where he didn't go after the djoker 2nd serve as much ...

Originally Posted by krosero

This part I bolded: you've rewatched the semi since you wrote this, so I don't know if this is still your argument about the UE's.

But it's still an interesting question whether better returning can produce higher UE's and thus lower AM's.

In these matches I don't think the argument works. I had forgotten how many times Federer came to net in the final: he had 68 approaches, nearly three times what he had against Djokovic. That, by itself, would not leave much room for baseline rallies in the final.

And now that we got the missing numbers for these matches, we can actually calculate how many baseline rallies there were. Just exclude all the aces, double-faults, net approaches and return errors, and you should have the # of baseline rallies almost exactly (it's not completely exact because we don't know if there were any points in which both players made approaches: but those points are rare).

So this is what I got:

86 baseline rallies in Fed/Djokovic: 40% of all points played.
99 baseline rallies in Fed/Murray: 34% of all points played.

So Fed/Murray may or may not have had better quality of returning than Fed/Djok, but even if it did, the result was not a greater number of baseline rallies leading to more UE's. Fed/Djokovic was the match that was played more from the baseline: and yet it's the match with lower UE's.

The returning in the final might have produced more baseline rallies, but Federer's charging the net essentially prevented that.

well, my argument was two pronged :

1. more returns in the finals resulting in more rallies ( not necessarily baseline ) , as we can see murray got in quite a few more returns and federer's % in was about the same as in the semis .... UEs can happen at the net as well , though not that many did in this particular final ...

2. the UE stats in the semi are off ( which I confirmed for myself by watching ), the UE stats in the final seemed ok to me going by my impression of watching the match ( again, can confirm only if I watch that match again )

[corners]

Originally Posted by abmk

well no authorative guide, but just some pointers :

for winners , its mostly simple :

clean winners : on which opponent did not get a racquet on
judgement winners : on which the opponent got a very very slight touch on

the judgement b/w what error is forced and unforced is more complicated and disagreements/doubts can occur :

if the error occurred due to pace, spin or angle of the opponent's shot or low bounce or ball dipping at the net or hit at great depth at the baseline or the player was on the run or stretching or if the opponent was at the net near to cutting off the easy angles, I'd say that error was forced

again, basically all cases in which the opponent forced the error in some way

otherwise the error should be classified as unforced ... ( DFs included )

Thank you. Thinking of Fed's comment on unforced errors. Is it possible that the same forcing shot hit by player A is an unforced error off the racquet of player B but an forced error off the racquet of player C? In other words, if player B is so skilled at returning forcing shots, is it possible that he is given an unforced error for failing to do so, while player B, not quite so skilled but failing to return the same shot, is given a forced error instead. If so, one would think that the great players, like Fed complained, are scored with more unforced errors than they deserve. But I guess for this discussion it doesn't matter, as we're mostly comparing great players.

[krosero]

Originally Posted by piece

Your point about surface affecting AM is well taken. You say, for instance, that fast/low-bouncing surfaces tend to have higher AMs. The reason you give for this seems to be twofold: (1) it's easier to execute aggressive plays on fast/low-bouncing surfaces; and (2) netplay is more common on fast/low-bouncing surfaces. Both of these two aspects (easier to force plays, more netplay) seem to positively affect AM, yet you talk as if matches played on the same surface (with the same speed) are roughly comparable with respect to AM. This would only be true if the amount of netplay is roughly constant between matches on a given surface.

It's not clear to me that their is this constancy - especially if we look across eras. Compare Borg-Vilas or Djokovic-Nadal at the FO to Laver-Rosewall. The former pairs remained almost exclusively at the baseline, while the latter approached the net in most points. I include Djokovic-Nadal because, while both camped out on the baseline, they also both go for winners when they have an opening, perhaps in contrast to the more conservative play of Borg-Vilas. This is worth mentioning because I'm going to guess Laver-Rosewall would have the highest AMs of the three pairs due to less unforced errors, but I don't want this attributed to the 'rally-all-day' style of Borg-Vilas. Rather, I think, Laver-Roswall will have the higher AMs than the other pairs because they had less opportunity to hit unforced errors due to the frequent net approaches. This would be the case even though the surface is held relatively constant.

You've talked about this yourself, and the lesson I think is that one can only use AM to compare match quality when holding the surface and level of net play relatively constant. Otherwise AMs can be easily inflated or deflated by factors unrelated to quality of play.

These are all real issues and because it's late at night I can't give a detailed reply. Some basic points though: so far I have not used AM's across eras. Same would go for winner/error differentials (which I've seen some posters do). There are too many variables.

The comparisons I like to do are matches on the same surface, preferably in the same venue and featuring the same two players: like the 3 Fed-Nadal Wimbledon finals; or the 5 straight years that Djokovic and Federer met at the USO; or the Fed-Delpo matches in '09. You can see just from the posts above how complicated the issues get even when variables are controlled this tightly

I have a feeling we'll be talking again about baseline play vs net play. Contrasting styles do present complications.

However, the stats are not always impacted the way you would expect. We all keep saying that long rallies tend to produce UE's more than matches filled with net-rushing: and that's true. But only up to a point. It doesn't always work out that way.

Take the two USO finals that Lendl and Wilander played in 1987-88. In '88 Wilander came in over 130 times, and there was a lot more net play than in the first meeting.

The first year approximately 27% of all the points were baseline rallies. The next year it was only 20%, but it's the '88 match that has the higher UE's and the lower AM's.

And above we were just comparing Federer's semifinal and final at Wimbledon last year. There was significantly more net play in the final, more baseline play in the semi: yet the final has higher UE's and lower AM's.

I'll have a look to see if there are more such cases. For now let me just caution that we should be careful about saying that net-rushing matches will have fewer UE's than wars of attrition between defensive players. Net-rushing is an aggressive play. Aggressive players tend not to keep their UE's down, because that's not their goal; and they're always trying to force the issue.

About Laver: I don't expect a Laver/Rosewall match at RG to have fewer UE's, and higher AM's, than Borg-Vilas and Nadal-Djokovic. That could be the case; I don't have the stats for Laver-Rosewall. But Laver did not temporize, and he did make errors as a result. On a slower surface that would make it harder for him to hit winners, you would expect him to make a good number of UE's and possibly a lot.

[krosero]

Originally Posted by abmk

well, my argument was two pronged :

1. more returns in the finals resulting in more rallies ( not necessarily baseline ) , as we can see murray got in quite a few more returns and federer's % in was about the same as in the semis .... UEs can happen at the net as well , though not that many did in this particular final ...

2. the UE stats in the semi are off ( which I confirmed for myself by watching ), the UE stats in the final seemed ok to me going by my impression of watching the match ( again, can confirm only if I watch that match again )

OK, I had assumed that you meant baseline rallies, because that's the assumption we've all been working with: baseline rallies are more likely to end in an UE.

Yes if you get a chance to do the final that would be great, because then the same method is being used.

[krosero]

Originally Posted by Bursztyn

We have been debating whether it is possible for the two players to raise their level of play without changing the AM's.

I would like to present a hypothetical scenario in which two players playing on two occasions on the same surface exhibit different level of play yet their calculated AM’s stay the same.

It is open to debate if such a scenario is realistic.

On the first day they played an average match; winners, forced and unforced errors were counted, and the AM's were calculated.

On the second day they played an excellent match, however the number of winners, forced and unforced errors was the same as on the first day (for the sake of simplicity I assume that the number of points in both matches was the same). How is it possible?

Winners;
The first player was hitting great shots, however the second player was also defending better than previously (had the second player been playing as well as on the first day, the first player would have had more winners than on the first day, had the first player been playing as well as in the first match he would have had less winners than in the first match). As a result the first player had the same number of winners on both occasions, and the same applies to the second player.

Forced errors;
Generally the same logic applies to forced errors. Both players committed the same number of forced errors as during the first match, however the shots that forced these errors were of the higher quality than the shots that forced errors in the first match.

Unforced errors;
Generally the same logic applies to unforced errors. Both players committed the same number of unforced errors as during the first match, however the points which ended in unforced errors were of the higher quality than points which ended in unforced errors in the first match. We have already mentioned that points that end in an unforced error may be of different quality (e.g. long neutral rallies versus double faults or return errors or short neutral rallies).

Very interesting, I'm going to give this some thought. A little mind-bending for me at this time of night.

[abmk]

Originally Posted by krosero

OK, I had assumed that you meant baseline rallies, because that's the assumption we've all been working with: baseline rallies are more likely to end in an UE.

Yes if you get a chance to do the final that would be great, because then the same method is being used.

just adding to my previous post :

1. federer having better success vs the weaker murray 2nd serve is already reflected in a significantly higher % of 2nd serve return points won than vs djoker's 2nd serve ... just that federer attacked the murray 2nd serve bit more resulting in a few more missed returns than if he would've just put them back into play ... different methods in different matches, but both appropriate for the kind of 2nd serves he was facing and both almost equally effective IMO ...

2. I just mentioned rallies, not just baseline rallies ... As we know , SnV points leave less chance for UEs, but there were very few SnV points in the final ..... most of the net points were points constructed from the baseline and then the players approached the net ... that does leave quite a bit of chance for UEs ... the % of success at the net does indicate well constructed points and very good net play for most part .....

[abmk]

Originally Posted by corners

Thank you. Thinking of Fed's comment on unforced errors. Is it possible that the same forcing shot hit by player A is an unforced error off the racquet of player B but an forced error off the racquet of player C? In other words, if player B is so skilled at returning forcing shots, is it possible that he is given an unforced error for failing to do so, while player B, not quite so skilled but failing to return the same shot, is given a forced error instead. If so, one would think that the great players, like Fed complained, are scored with more unforced errors than they deserve. But I guess for this discussion it doesn't matter, as we're mostly comparing great players.

well, I would say it is possible, though not deliberately, but at a subconscious level ; you'd expect great players to miss less ....

see for example rafa missing the BH pass vs djoker in the final set of the Aussie Open final in AO 2012 ... it was a doable pass , even more so for rafa, though not an absolute gimme ... say if roddick had missed it, how many would've raised eyebrows ? and roddick was no slouch himself ...

just that one has to be be vigilant enough while making these judgements ...

[krosero]

Originally Posted by abmk

just adding to my previous post :

1. federer having better success vs the weaker murray 2nd serve is already reflected in a significantly higher % of 2nd serve return points won than vs djoker's 2nd serve ... just that federer attacked the murray 2nd serve bit more resulting in a few more missed returns than if he would've just put them back into play ... different methods in different matches, but both appropriate for the kind of 2nd serves he was facing and both almost equally effective IMO ...

2. I just mentioned rallies, not just baseline rallies ... As we know , SnV points leave less chance for UEs, but there were very few SnV points in the final ..... most of the net points were points constructed from the baseline and then the players approached the net ... that does leave quite a bit of chance for UEs ... the % of success at the net does indicate well constructed points and very good net play for most part .....

1. Federer gained something by being aggressive with Murray's second serve, and the cost was a few more missed serves, because he was going for them. Agreed on that. I think you're saying that when we look at the fact that his Return In % was basically the same as what it was in the semis we should take the missed serves into account. He may have missed them, but he also gained something by attacking the second serve. I could see that. There's a good case his returning quality in the two matches was very similar.

2. Not sure I understand you here. Our working assumption is that net play of any kind, not just SV, reduces the chances for UE's because only 1 player (the one rushing the net) can now make an UE; the defender will either make a winner or a forced error.

I don't think you're saying that SV net play results in more UE's than net play behind approaches (or are you?)

Keep in mind we were debating why there were more UE's scored in the final than in the semi. That's the issue I'm talking about.

Are you saying that the baseline rallies in these matches -- the points on which all 4 players stayed back throughout the point -- were different in the final, and more likely to end in UEs, because Federer and Murray were trying to get into net?

[pc1]

Krosero,

On the matches that you've charted, did you find that the average AM varied according to the era? For example did you believe 1968 to 1985 had different AMs than 1985 to 2000 and that would differ from 2001 to the present?

[corners]

Originally Posted by abmk

well, I would say it is possible, though not deliberately, but at a subconscious level ; you'd expect great players to miss less ....

see for example rafa missing the BH pass vs djoker in the final set of the Aussie Open final in AO 2012 ... it was a doable pass , even more so for rafa, though not an absolute gimme ... say if roddick had missed it, how many would've raised eyebrows ? and roddick was no slouch himself ...

just that one has to be be vigilant enough while making these judgements ...

Yeah, your Rafa vs. Roddick backhand error is just the type of thing I was thinking of.