ATP WTA GS US Open 8/26 - 9/8 2024

[ashkor87]

No, if they get the same kind of call wrong, the error rate would be the lower of the two, namely 2%

[FredX]

No, if they get the same kind of call wrong, the error rate would be the lower of the two, namely 2%

And if you have both, which do you defer to if there is a discrepency? Seems you would have to defer to Hawkeye given it's overall higher success rate, so I don't see how having both could work.

I do wonder what conditions might contribute to Hawkeye being inaccurate. The technology is predictive based on assumed trajectory - does that mean it's 99.8% accurate in perfect weather, but only say...92% accurate when that hurricane is threatening to blow in? Do certain types of shots and spins lead to more errors?

[ponchi101]

No, if they get the same kind of call wrong, the error rate would be the lower of the two, namely 2%

No.
If the lines person makes the call, and he has a 98% success rate, he will miss 2 out of every 100 calls made.
The player then challenges and Hawkeye comes into play. Hawkeye will then miss 2 out of those 100 CHALLENGES. So, 0.02 X 0.02 gives you the rate of 0.0004.
You cannot assume that the line judge and Hawkeye will make the SAME wrong call, because then it is not a random rate of failure.

[FredX]

No, if they get the same kind of call wrong, the error rate would be the lower of the two, namely 2%

No.
If the lines person makes the call, and he has a 98% success rate, he will miss 2 out of every 100 calls made.
The player then challenges and Hawkeye comes into play. Hawkeye will then miss 2 out of those 100 CHALLENGES. So, 0.02 X 0.02 gives you the rate of 0.0004.
You cannot assume that the line judge and Hawkeye will make the SAME wrong call, because then it is not a random rate of failure.

What do you mean by a random rate of failure? There's no indication that Hawkeye gets 2% of all shots wrong randomly as if it were the margin of error of a random probability sample...I'm sure the 2% it gets wrong are very close calls, the same close calls that lines people would miss. And if Hawkeye gets 2% of all calls wrong, that doesn't mean it will get 2% calls wrong that are disputed by the player and line judge, that percentage would logically be much larger.

[ponchi101]

The errors have to be random, or otherwise, it is a system failure. The system, as you say, must be calibrated and it certainly does not make some mistakes that would be flagrant. If, for example, the system were to call 2% of all balls that land squarely in the middle of the back box out, then that would be random, but completely useless.
You are right in that the definition of bad call has to be attached to a measurement of "close call". You have to define such close calls; are they balls that land within 2 mm of a line, be it in or out?
And how they measure the rate of errors by the lines people? Because if they measure those by using Hawkeye, then you have a circularity: the line judges miss 25% of calls when measured by Hawkeye, but the point that we want to know is how good are the line judges Vs Hawkeye, but using Hawkeye to measure them is circular.

[ashkor87]

If the USO is going to be played on such fast courts, Rybakina, Sabalenka will not do well...swiatek and gauff are the best movers on the tour, they will do ok ..so will Raducanu and Leylah ...on the men's side, Paul will do better than Fritz, alcaraz and DeMinaur will do well, so will Sinner..

Leylah and Raducanu did so well a couple years ago at the USI because the court was very fast..it was not a fluke

[ashkor87]

Andreeva is really improving with every run...she could be a force at the USO...she is quick, her defense is great...

[ashkor87]

USOpen probabilities

Sinner 35%
Alcaraz 35
djokovic 25
Field 5

Swiatek 35%
Sabalenka 25
Rybakina 15
Coco 5
Andreeva 5
Pegula 5
Osaka 5
Field 5

[ponchi101]

You will never learn
Starting in 2015, the field has won 5 times: Penetta, Sloane, Osaka, Andreescu and Raducanu. It has also placed 3 other finalists (Vinci, Keys and Fernandez).
I know that you don't like the "open to anybody" concept. But the field at 5%, when we so constantly have new winners at slams that are ranked below the top ten (Barbora Krejcikova at W is the latest) is simply not looking at the data.
And...
Not including Paolini, right now, is kind of not looking at the whole picture. RU at the last two slams, and she is playing well in Cincy. I would give her a better chance than Osaka.
Rybakina at 15% is too high.

[ashkor87]

Ok, let us agree to disagree..! We shall see in a couple weeks who is right.

[ashkor87]

Osaka and Andreescu would have been long shots only for people who didn't follow tennis those years. Andreescu was undefeated on hard courts till then, and Osaka had already won big hard court tournaments earlier.
Re Paolini, I like her a lot -remember, I am the one who said she would be a force at Wimbledon..but I don't give her any chance of actually winning a major, she lacks that indefinable something...
I don't give Krejcikova much chance either, because she needs too much time to hit her shots, and the courts will be fast
It is not data, it is judgement I am calling on.

[skatingfan]

Osaka, and Andreescu have no form going into the US Open. They will be lucky to make the 3rd round, but happy to be wrong. I just don't see them suddenly pulling it together. It's not their pattern.

[ponchi101]

Osaka with a very interesting quote. Roughly, that she feels like her body is not hers.
Must be tough to play tennis with such a feeling.

[ptmcmahon]

You will never learn
Starting in 2015, the field has won 5 times: Penetta, Sloane, Osaka, Andreescu and Raducanu. It has also placed 3 other finalists (Vinci, Keys and Fernandez).
I know that you don't like the "open to anybody" concept. But the field at 5%, when we so constantly have new winners at slams that are ranked below the top ten (Barbora Krejcikova at W is the latest) is simply not looking at the data.

Hey now, he used to say 0% some of the time... at least I got him out of that habit

[ashkor87]

USOpen probabilities

Sinner 35%
Alcaraz 35
djokovic 25
Field 5

Swiatek 35%
Sabalenka 25
Rybakina 15
Coco 5
Andreeva 5
Pegula 5
Osaka 5
Field 5

Now that it has been revealed that the court is going to be quick (42?)

revised probabilities:

Sinner 35%
Alcaraz 35%
Djolovic 20%
Medvedev 5%
Field 5%

Swiatek 25%
Sabalenka 15%
Rybakina 15%
Leylah 15%
Andreeva 10%
Coco 5%
Raducanu 5%
Pegula 5%
Osaka 4%
field 1%

Raducanu and Leylah thrived on the fastest USO court we have yet seen, there is always a chance of a repeat (though not as high as I would hope for!) - that was not a fluke. Gave the field 1% just to evade the usual comments! but it is certainly unusual for 4 players to make up 70% of the probabiity space.