Australian Open

[jimlosaltos]

I don't doubt those are the posted stats. Just not sure I believe them. As I posted before a USTA insider tells me that on the groundstrokes any data above 100mph is "unreliable" what ever that means...

John, let's see if I can be more concise and clear without the fog of nighttime <g>.

I'd be surprised if any inaccuracies in the HawkEye data were great enough to alter the basic trends they show.

Let's say the high end measurements are off by 4%, which would be a huge error. Then the top groundstroke speeds of 130 MPH, if inaccurate by +/-4% would actually be 124 - 134 MPH.

So, the extremes, the highest speeds for groundstrokes would still be overlapping with service speeds. That's amazing & yet worth questioning.

The second trend the HawkEye data shows is that the highest groundstroke speeds for most of the top players has moved from several players reaching 100 MPH during a tournament 10 years ago, to most everyone in the top 20 not named Diego Schwartzman, hitting 120 mph on one or both sides from time to time. That, to me, is the bigger takeaway. So, again assume it's off by 4%, then that becomes the top 20 regularly reaching 115 - 125 MPH, not in every game, but over the course of a tournament. That's a big leap from peak Fedal years.

In order to change those two conclusions, the HawkEye errors would have to be, say, over 10% -- which would be so egregious, the reliability of the whole system would be called into question.

There's another interpretation to the USTA official's comment about inaccuracy. That would be that the system has trouble with so-called "Edge Cases". That is, the measurements are accurate most of the time, but have trouble with some difficult conditions. For example, when a player is at the back wall fewer cameras have coverage of the racket striking the ball. Going from bright sun to dark shadow with low contrast but cause problems. But even then, measurements of typical groundstrokes struck from the normal playing area should be accurate.

When I pulled data for the earlier TPN article, I removed data on shots that shows "Spin N/A", or unusual flight paths for the balls, to reduce possible issues like that.

I spent some time searching for information on accuracy of HawkEye used in Major League Baseball. Unlike tennis there are independent studies of HawkEyes accuracy there. Academics discuss the errors, but in fractions of a percent, nothing approaching what would fundamentally change what the groundstroke stats show us. One issue is "calibrating for stadiums". I don't know what they believe varies. But the tennis HawkEye data, paltry and erratically shared as it is, is consistent for players across different events. If Caspar Ruud hits 120MPH and often close to 4,000 RPMs, that is shown at different sites, with different sets of equipment.

Well, I failed in my goal of conciseness. Sorry <g>

[jimlosaltos]

Forehand Speeds at AO 2017

For perspective, some of you might like this graphic I dug up for you from the NYT giving forehand speeds from the Australian Open in 2017.

Since averages can mislead, I like the way the horizontal lines show the average on the left of each line and the maximum speed for that player on your right. Relevant to our discussion, the fastest speed shown is about 103 MPH by Rafa, with 15 men reaching 100 MPH. Note: This is from the Tennis Australia stat group, and their methodology takes out outliers, i.e. the fastest and slowest shots are removed.

filedata/fetch?id=99592&d=1674937074&type=thumb

[stroke]

Novak routines Stef 1st set. Odds now show Novak at a 92.5% implied probability of winning this match.

[stroke]

Stef played much better in 2nd set, showed a lot of belief. Lost 2nd set tiebreaker. Just too many loose errors off both sides to get in done vs Novak.

[stroke]

Stef to his credit never lost belief, fought to the end. I guess it is kinda like pro wrestler MJF might say, The Big 3 are just better than you, and you know it.

[arturohernandez]

Well put. Djokovic learned nothing from the disastrous Adria Tour.

I'd add that it is a big leap from making an individual choice to not get vaccinated to openly promoting pseudo-science above modern healthcare, as Djokovic did when he promoted a scam artist's fake alien pyramids and the healing power of their tunnels. People are paying to visit this hoax because of his celebrity.

Magical thinking works on the tennis court. Dream big and you can do it as he just said in the trophy presentation. Novak dreams big. He makes it big and his dreams come true. So, if you dream big it can come true.

That is how he wins. He believes he can win. it is magical thinking that applies to the controlled environment of a tennis court.

The only amazing thing is that just four years ago, Fed almost beat him at Wimbledon. Now that my flat ball theory is dead. I am still trying to figure out why not one player in the last 20 years has emerged that is as good as the big 3. Every generation before them had a new player that would appear and dominate. It can't be that these three are THAT special.

Of course, Alcaraz was missing, and he seems to have the kind of game and intensity to win against Novak. Let's hope he can get healthy and stay healthy going forward.

[arturohernandez]

Forehand Speeds at AO 2017

For perspective, some of you might like this graphic I dug up for you from the NYT giving forehand speeds from the Australian Open in 2017.

Since averages can mislead, I like the way the horizontal lines show the average on the left of each line and the maximum speed for that player on your right. Relevant to our discussion, the fastest speed shown is about 103 MPH by Rafa, with 15 men reaching 100 MPH. Note: This is from the Tennis Australia stat group, and their methodology takes out outliers, i.e. the fastest and slowest shots are removed.

filedata/fetch?id=99592&d=1674937074&type=thumb

I always thought the whole women hit as fast as men argument was bogus. I am not trying to argue for superiority here. I loved watching the women's final because it was different than the men's final. I always thought that men hit a heavier ball which more than compensated for the speed similarity. Now I realize that the mean is just that a mean. It doesn't not capture the range of forehands. This range thing makes sense. Men could hit every ball harder but it does not have the same effect.

[jimlosaltos]

I always thought the whole women hit as fast as men argument was bogus. I am not trying to argue for superiority here. I loved watching the women's final because it was different than the men's final. I always thought that men hit a heavier ball which more than compensated for the speed similarity. Now I realize that the mean is just that a mean. It doesn't not capture the range of forehands. This range thing makes sense. Men could hit every ball harder but it does not have the same effect.

Lots of good issues in that.

I was going to post this in your slice thread, but while I'm typing it fits here too. ONE reason Ash Barty's slice is (was, sadly) so effective is she hit her topspin forehand with RPMs up there with the ATP clay courters, up to 3,450 RPMs at Roland Garros if I remember correctly. Quite a change from her forehand jumping off the court at you, to her skidding slice.

And, on range of velocity, I found this on Djokovic from AO. ND is hitting both his forehand and his serve harder than in the past (Goran's influence, no doubt). The red dots here are "Greater than 130 KMH or 80 MPH". Without counting them it looks like a lot more red dots than slower ones. Note "greater" not what the peak speed, which is rarely reported of late. For perspective, Jim Courier said two years ago that Nikoloz Basilashviliwas the "hardest hitter on the tour, reaching 80 MPH average on both sides. That's the best by a small margin on the forehand side, and a big one on the backhand".

filedata/fetch?id=99612&d=1675101763&type=thumb

[jimlosaltos]

I always thought the whole women hit as fast as men argument was bogus. I am not trying to argue for superiority here. I loved watching the women's final because it was different than the men's final. I always thought that men hit a heavier ball which more than compensated for the speed similarity. Now I realize that the mean is just that a mean. It doesn't not capture the range of forehands. This range thing makes sense. Men could hit every ball harder but it does not have the same effect.

Arturo, I pulled these two for you that might be of interest.

First shows that Sabalenka averaged 76 MPH on forehands, red = winners. Lots of short and wide. Fm ESPN

From memory, 76 MPH is just about what the Big 3 averaged on forehands a few years ago.

filedata/fetch?id=99616&d=1675111645&type=thumb

This shows one of Sabalenka's backhand winners, short, fast and flat. Uncharacteristically for a two-hander she favors the low ball in no-man's land and can get it in with pace, and without needing spin (unless she's missing and then it can all go badly) Amazing ability to hit winners with zero margin. I'm not sure how the "height" can be 3.3 feet since the net is 42 inches <g> ticked the net? Height at impact, perhaps?

filedata/fetch?id=99617&d=1675111656&type=thumb

#

[stotty]

The problem I have with all this is that I walk around Wimbledon every year watching tennis on the show courts and the outside courts and I can say with confidence the women aren't hitting the ball as hard as the men...or anywhere near.

The other problem I have is some serves appear to be going slower than others yet get clocked quicker.

I don't have great faith in these ATP speed guns, or hawkeye for that matter.

[jimlosaltos]

The problem I have with all this is that I walk around Wimbledon every year watching tennis on the show courts and the outside courts and I can say with confidence the women aren't hitting the ball as hard as the men...or anywhere near.

The other problem I have is some serves appear to be going slower than others yet get clocked quicker.

I don't have great faith in these ATP speed guns, or hawkeye for that matter.

Since there's zero transparency from the tennis bureaucracy on these systems, among other things, who can say with 99% certainty? Not me.

As for hitting the ball hard, Sabalenka is bigger and more muscular than some of the ATP top 50 players.

I doubt Alex di Minaur or Diego Schwartzman would want to meet her in a fight, or even arm wrestling. <g>.

[don_budge]

“If your experiment needs a statistician, you need a better experiment.”

“Most people use statistics like a drunk man uses a lamppost; more for support than illumination.”

[stroke]

Since there's zero transparency from the tennis bureaucracy on these systems, among other things, who can say with 99% certainty? Not me.

As for hitting the ball hard, Sabalenka is bigger and more muscular than some of the ATP top 50 players.

I doubt Alex di Minaur or Diego Schwartzman would want to meet her in a fight, or even arm wrestling. <g>.

I don't know about a fight, never thought of that, but I do know what would happen if they played tennis.

[don_budge]

“99 percent of all statistics only tell 49 percent of the story.”

[stroke]

I do think post match statistics tell a lot. Novak vs Tsitsipas, stats showed the Stef bh actually held up well. He did not have a real bad error to winner ratio as he often does in losses. But his forehand let him down. Way more errors off that side than Novak, even though their winners were about the same.