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Old 01-29-2013, 08:18 AM   #218
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Originally Posted by krosero View Post
I am still very skeptical that higher quality of returns can produce lower AM's. It's a valid theory but I don't think there's good evidence for it -- and even in theory, a lot of things have to fall exactly into place for better returning to produce lower AM's.

First of all, if someone is producing quality service returns in the sense that he's cutting down on his unforced errors on the return, then that will immediately raise the AM's. So in theory, when we're comparing two matches and saying that one match has low AM's because it featured better returning, we need the better returning NOT to manifest itself as fewer UE's on the return. It can only manifest as better returns on huge serves that are not normally returned. In other words, the player whom we're saying is doing the quality returning cannot be producing better returns on medium/slow serves that are sometimes dropped into the net or driven out (UE's); if the player is being more careful with such serves and putting them back into play, then he's cutting down on the UE's in the match and raising the AM's.

That, already, strikes me as an unusual situation: for a quality returner to manifest his better returning, not on easy serves, but on hard serves. I'm not saying it can't happen: sometimes you do see players who return better when they have pace to work with; but players who tend to dump off-pace serves into the net are not the kind of players we usually think of as quality returners; and Djokovic is certainly not one of those inferior returners.

Another thing that must happen is this: the superior returner gets these tough serves back into play and the resulting rallies end to a significant degree in unforced errors. That again does not strike me as likely, because if a receiver somehow gets his racquet on a humongous serve and drives it back, when the server expected to see a weak return or no return at all, it's very likely that the server will be forced into an error. Djokovic does that countless of times to his opponents (just like Connors used to do).

It's true that Murray sometimes barely gets his racquet on the ball and his return floats softly, and deep, just inside the opposite baseline; and then a long rally ensues which sometimes ends in an UE. But Djokovic's superior returning very often manifests itself as a forcing return that shocks the server or throws him off balance and forces him into an error. And even when the server is not forced into an error and manages to scoop the ball back up, Djokovic at that stage is very often in a position to put away the next ball, or to force an error.

Superior returning off BIG, tough serves CAN end up in unforced errors at the end of the rally but very often it doesn't work that way.

When we tested this theory in the Djokovic/Murray/Fed matches last summer in the last two rounds at Wimbledon, you argued that Murray returned better than Djokovic and put more balls back into play, thus presenting more opportunities for UE's. But you saw my calculations: the number of extra balls that Murray put back in play cannot have resulted in more than 2 or 3 extra UE's, if that.

Additionally, you counted UE's on the return in both matches, and you found Murray making fewer of those errors than Djokovic did. That makes a lot of sense, given Murray's style of returning and style of play in general. But if that's the case -- if Murray returned better than Djokovic in those matches and the quality of Murray's returns manifested as fewer UE's -- then that just about the settles the question in my mind. Murray's superior returning, in the final, was REDUCING the number of UE's in that match, and raising the AM's. So if the final has lower AM's than the semifinal between Fed/Djokovic, we need to find some cause other than Murray's superior returning.
actually , by my stats

32 UEs in 133 rallies in the semi (24.06%)
49 UEs in 206 rallies in the final (23.8%)

referring back to your post :

if we make murray's return % to 56, it comes to 72 returned serves out of 128 rather than the actual 99 out of 128 ... so difference is 27 serves , not 17 serves ...

if we make 20-21 accounting for fed's superior serving in the semis...... no of UEs produced by getting more returns into play ~ 5

earlier calculations for AMs:

semis :

federer : 31.95%
djokovic : 26.4%

finals :

federer's AM = 29.5%
murray's AM = 24.7%

if we 'remove' these 5 UEs

federer's AM = 31.25%
murray's AM = 26.4%

that brings the AMs in these matches very close ...

having said that murray's superior returning on the first serves doesn't seem to have as much of an effect on the no of UEs as I initially thought ....

perhaps better returning of 1st serves has more of an effect on slower surfaces where % of UEs per no of baseline rallies is more !?
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