Stupid stats question

angry1 · Lower Club Player

Stupid stats question

steven · Tennis legend

As far as I understand it, service winners include serves that the receiver gets their racket to but is unable to return as well as aces, unless the failed service return is an unforced error.

An unforced error is when the player has time to prepare and position himself or herself to get the ball back in play and makes an error, so unreturned first serves will tend to be counted as service winners whereas unreturned second serves have a greater chance of being classed as UEs.

-- Edited by steven on Wednesday 8th of July 2009 02:26:23 PM

indiana · Tennis legend

One major reason why both Murray and Federer outaced Roddick is because they have the anticipation to at least get a racket to the ball.

But clearly many many more of Roddick's serves were pretty unreturnable so what Steven suggests re many of these counting as winners does make sense.

I do think the ace stats would be pretty high for Roddick serving to Roddick smile

angry1 · Lower Club Player

steven wrote:

As far as I understand it, service winners include serves that the receiver gets their racket to but is unable to return as well as aces, unless the failed service return is an unforced error.

An unforced error is when the player has time to prepare and position himself or herself to get the ball back in play and makes an error, so unreturned first serves will tend to be counted as service winners whereas unreturned second serves have a greater chance of being classed as UEs.

-- Edited by steven on Wednesday 8th of July 2009 02:26:23 PM

Thanks Steven,that was all I could think of but still seems incompatible with my previous understanding of what constitutes a winner.I always believed winners were shots opponents couldn't get to.

That means a first serve return blasted into the net is a winner for the sever but, a return that forces the opponent to hit into the net isn't for the returner.That to me makes no sense.

Surely there should just be a separate unreturned 1st serves stat or ignored altogether, not messing up something of potential interest.

I know stats don't tell you the whole story but as a short hand way of understanding things winner-ue count tells you something about how a player is playing IMO.I don''t see any way at Wimbledon to extract service winners to get that.

All the previous is with the disclaimer that stats are still a matter of opinion in many cases.

Madeline · Admin:Moderator + Tennis Legend

Or Roddick serving to Karlovic, and vice versa. . .

Count Zero · Tennis legend

exactly whilst high ace count looks good, an unreturnable serve is just as good isn't it, and a lot is down to opponents awareness. i'm not talking about ones where the opponent gets to it and it just clips the net or lands inches long, but the ones where they frame it off into the crowd. it's not an ace as such, but might as well be.

as an aside i was just looking through boggo playing activity and they have full stats available for all his matches now in 2009, inc the challenger one. a nice addition. i assume it will be the same for all challenger matches. can at least give us an idea of what happened in matches where we only get a score. esp as you can see breakpoints etc.

angry1 · Lower Club Player

indiana wrote:

One major reason why both Murray and Federer outaced Roddick is because they have the anticipation to at least get a racket to the ball.

But clearly many many more of Roddick's serves were pretty unreturnable so what Steven suggests re many of these counting as winners does make sense.

I do think the ace stats would be pretty high for Roddick serving to Roddick

Who do you reckon would be lowest?My imaginative answer would be Rafa.

Federer's as I think of it true winner count must have been miniscule against Roddick, 57 minus his non ace service winners in 77 games.

indiana · Tennis legend

Re the winners stats, I do quite take Angry's point that if any unreturned first serve is automatically counted as a winner that doesn't seem quite right. And if someone is making some judgement on what first service ( when touched ) should really count as a winner and when not, then that seems to be a hell of a difficult if not pretty impossible job, and interpretations would certainly vary. And some guys, eg Karlovic boom down many second serves too, so what's the position there if they are touched ?

Anyone know for certain how winners are decided, on first serve, second serve and in later play ? It would really be quite interesting to know.

-- Edited by indiana on Wednesday 8th of July 2009 04:00:10 PM

indiana · Tennis legend

Hmm, interesting. Check Karlovic's stats v Federer in the Wimbledon quarter finals.

23 aces and 29 winners ( IN TOTAL ). Karlovic surely had a whole lot of unreturned ( and indeed pretty unreturnable ) serves in which Federer got some sort of racket to.

That pretty much proves to me that on serve only the aces are being counted as winners.

This would fit in with angry's original thoughts, and mean they could be subtracted straight off to tell you for instance that Karlovic achieved 6 winners in general play.

-- Edited by indiana on Wednesday 8th of July 2009 04:16:23 PM

-- Edited by indiana on Wednesday 8th of July 2009 04:19:40 PM

Count Zero · Tennis legend

well its always got to be a judgement call by someone, i am sure there are guidelines, but this is a sport so it can be nothing other than that.

what's a drop shot that is chased down and returned into the net? a UE? or exactly the same drop shot that the player leaves cause they are too tired and think they will net it anyway? a winner.

personally i don t think its something one should worry about too much. watch a match and make your own decision.

however i would assume that a winner is:

a) in open play: when your opponent doesn't get his racquet to it; a 'clean winner' as such
b) from a serve: when you opponent doesn't get the return near the doubles court boundaries

a 'winner' that your opponent gets to but cant return gets classed as a forced error.

angry1 · Lower Club Player

indiana wrote:

Hmm, interesting. Check Karlovic's stats v Federer in the Wimbledon quarter finals.

23 aces and 29 winners ( IN TOTAL ). Karlovic surely had a whole lot of unreturned ( touched ) serves.

That pretty much proves to me that on serve only the aces are being counted as winners.

This would fit in with angry's original thoughts, and mean they could be subtracted straight off to tell you for instance that Karlovic achieved 6 winners in general play.

-- Edited by indiana on Wednesday 8th of July 2009 04:16:23 PM

That makes a lot more sense to me.I did think it was an implausibly low number for Federer.Your example proves to my satisfaction that at least sometimes, touched serves don't count as winners.

indiana · Tennis legend

My overall guess would that a winner on all occasions needs to be untouched by the opponent.

An unforced error is a bit in the eye of the beholder, as to how much pressure the player was under, but I am sure the stats folk have guidelines as much as is possible.

I have always understood, and even more so now, that many points end with neither a winner or an unforced error.

steven · Tennis legend

I've been looking into this a bit more and it seems that even in normal play, you can be credited with a winner even if your opponent gets their racket on the ball.

In post 6 on the thread at http://tt.tennis-warehouse.com/showthread.php?p=2456237, the poster says that they contacted Dr Leo Levin (long-time tennis statistician and the inventor of the term "unforced error" about this and he said that winners are credited even on non-serves "if the ball is tipped off towards the sides or into the stands," whereas "if the opponent directs it back toward the net, and the ball reaches the net 'on the fly', it's a forced error" and that the goal of having such judgment calls was to appropriately reward the shot. The operative question being, was the opponent able to make any kind of reasonable attempt at a reply? If not, the point is credited as a winner rather than an error.

However, when asked at http://www.tennis.com/yourgame/asktheeditors/asktheeditors.aspx?id=1432 when a shot should be designated an unforced error, in part of his reply Dr Levin says that "most missed returns of first serves are considered to be forced errors - forced by the pace and placement of the opponent's serve," which muddies the waters a bit, though it doesn't completely contradict the above.

He also says that "many, if not most return errors against second serves, would be unforced errors since most second serves are just means to get the point started and do not put extra pressure on the receiver," which makes the same distinction as I did in my original reply, though I agree that some players' second serves should probably be treated as first serves for this purpose.

There does seem to be plenty of room for subjectivity here and while I'm sure each big tournament trains its data collectors to be as consistent as possible, it may well be that at some tournaments, only shots the opponent doesn't get a racket to are counted as winners, while others split between counting winners for first serves where there isn't really a play on the ball but the opponent just about gets a racket to it, and others follow the wikipedia definition mentioned in another thread about this at http://tt.tennis-warehouse.com/showthread.php?p=2611183, i.e. only count such unreturnables as winners if they are (first) serves.

That's as clear as mud then wink

P.S. I think the "points won on serve counted as winners at Roland Garros" thing they are talking about at that last link is a red herring - that is indeed what appeared to be happening I'm pretty sure that was just a problem on the RG website.

-- Edited by steven on Wednesday 8th of July 2009 04:30:59 PM

indiana · Tennis legend

angry1 wrote:

indiana wrote:

Hmm, interesting. Check Karlovic's stats v Federer in the Wimbledon quarter finals.

23 aces and 29 winners ( IN TOTAL ). Karlovic surely had a whole lot of unreturned ( touched ) serves.

That pretty much proves to me that on serve only the aces are being counted as winners.

This would fit in with angry's original thoughts, and mean they could be subtracted straight off to tell you for instance that Karlovic achieved 6 winners in general play.

-- Edited by indiana on Wednesday 8th of July 2009 04:16:23 PM

That makes a lot more sense to me.I did think it was an implausibly low number for Federer.Your example proves to my satisfaction that at least sometimes, touched serves don't count as winners.

angry, I really think it actually proves no touched serves are being counted. Karlovic surely had many not just unreturned, but absolutely unreturnable touched / framed etc serves.

So you can now I think happily do your subtractions for in play winners smile

indiana · Tennis legend

I read what you report this evidently distinguished gentleman as saying Steven, but someone then explain to me Karlovic's stats v Federer ?!

Are you telling me apart from aces he only had 6 more unreturnable serves or general winners in the whole match ?

PS : Actually on further reading I think there is maybe some confusion between winners and the forced v unforced error issue. I think that guy has more been trying to explain where a shot does not count as an unforced error. That does not mean it counts as a winner to the other player. As I previously said, many rallies will end with neither a winner or an unforced error.

-- Edited by indiana on Wednesday 8th of July 2009 04:40:46 PM