Coup Droit wrote:

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L16: (1) Billy Harris WR 110 def (Q) Hiroki Moriya (JPN) WR 432 7-5 6-3

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 Apart from the title of course, 3 wins from the top 100. Just saying ...

Great to see , well done Billy!

JonH comes home wrote:

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Let's hope he achieves what he deserves this week.

The 8 players left, though, arent slouches.

Not sure how the bookies see it but Tennis Abstract rate Billy as a bit of an outsider to take the title - Brandon Holt is up next and they rate it 59-41 in his favour to beat Billy. If Billy does come through, Vacherot is rated above him and Holt and Vacherot are the top 2 overall. Of the 8, Billy is rated a 10% chance of the title (so less than an even chance in an 8 players field) and 5th favourite overall.

You show them Billy!

Player SF F W
(1)Billy Harris (GBR) 40.6% 18.5% 10.2%
(6)Brandon Holt (USA) 59.4% 32.7% 21.0%
Valentin Vacherot (MON) 61.5% 32.8% 20.9%
(8)Alexis Galarneau (CAN) 38.5% 16.0% 8.4%
(5)Ugo Blanchet (FRA) 62.3% 33.0% 13.8%
Khumoyun Sultanov (UZB) 37.7% 15.5% 4.7%
Dalibor Svrcina (CZE) 71.3% 41.2% 18.5%
(Q)Ilia Simakin (RUS) 28.7% 10.3% 2.5%

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 excuse my ignorance .. if Billy is an outsider to take the title then how did he get seeded 1? could explain how you think this came about? Thanks

B00thy wrote:

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JonH comes home wrote:

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Let's hope he achieves what he deserves this week.

The 8 players left, though, arent slouches.

Not sure how the bookies see it but Tennis Abstract rate Billy as a bit of an outsider to take the title - Brandon Holt is up next and they rate it 59-41 in his favour to beat Billy. If Billy does come through, Vacherot is rated above him and Holt and Vacherot are the top 2 overall. Of the 8, Billy is rated a 10% chance of the title (so less than an even chance in an 8 players field) and 5th favourite overall.

You show them Billy!

Player SF F W
(1)Billy Harris (GBR) 40.6% 18.5% 10.2%
(6)Brandon Holt (USA) 59.4% 32.7% 21.0%
Valentin Vacherot (MON) 61.5% 32.8% 20.9%
(8)Alexis Galarneau (CAN) 38.5% 16.0% 8.4%
(5)Ugo Blanchet (FRA) 62.3% 33.0% 13.8%
Khumoyun Sultanov (UZB) 37.7% 15.5% 4.7%
Dalibor Svrcina (CZE) 71.3% 41.2% 18.5%
(Q)Ilia Simakin (RUS) 28.7% 10.3% 2.5%

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 excuse my ignorance .. if Billy is an outsider to take the title then how did he get seeded 1? could explain how you think this came about? Thanks

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 As I say, the bookies may see it differently. And as Indy says, there is another way of looking at it. Tennis Abstract, in terms of how they do it, use an algorithm they have created that is ELO. In essence, it takes the players recent form and who they have played and assigns an ELO rating that is then adjusted for surface; they then generate 1000's of simulations of the match and the % shown is the output of that simulation exercise. 

Billy has an ELO rating of 1597 currently, which places him 168 in the TA view of the current rankings; as opposed to his real ranking of 110 or whatever it is that gave him the seeding. They assess Holt has an ELO of 1653 and a ranking of 134, which is better than his actual world ranking (and why he has a lower seeding). 

They put these ELO's together, adjust for surface in some way, and then run the simulations. They do that for every match in the draw, through each round in terms of each potential match up and work out round by round percentages and an overall view.

In Glasgow, for example, Evo is rated as tournie favourite at 28.4% as it stands; Jake is also rated favourite in Pau at 43.1% - the percentages change as every match finishes and is updated as a player winning a match takes another out of the draw and changes the relative positions of each player and their potential progress through the draw - so if you check these percentages in an hour or two, they could vary if the field has changed

https://www.tennisabstract.com/current/2025PuneChallenger.html

https://www.tennisabstract.com/current/2025GlasgowChallenger.html

https://www.tennisabstract.com/current/2025PauChallenger.html

https://www.tennisabstract.com/current/2025ATPDoha.html

In Dubai, Jack is currently third favourite of the QF field left. Alcaraz is the favourite, obviously

https://www.tennisabstract.com/ is the main site link and you can see lots of other stuff there as well as womens draws and analysis. They only analyse it for ATP/WTA main tour and Challenger/125 events though, not ITF

 This explains how ELO ratings work and how it flows through to predictions at a match level

https://tennisabstract.com/reports/atp_elo_ratings.html

A 100-point difference in Elo ratings implies that the favorite has a 64% chance of winning a best-of-three-set match; 200 points implies 76%, 300 points implies 85%, 400 points implies 91%, and 500 points implies 95%. In best-of-five, the favorite is more likely to win, by a factor that depends on the best-of-three odds.

Surface-specific Elos--"hElo," "cElo,", and "gElo"--are a mix of overall Elo and separate ratings generated using only results on the given surface. These ratings give more accurate forecasts for individual matches.   

-- Edited by JonH comes home on Thursday 20th of February 2025 11:48:33 AM

Yes Jon, as you decribe, the Tennis Abstract ratings and %s make assessments based on many factors such as general form, opponents played, surfaces etc. The bookies will also do their own assessments based on presumably not dissimilar criteria to arrive at their match odds and favourites.

Whereas of course seedings come purely from players' positions in the official world rankings, which are in turn based purely on ranking points from the last 12 months, whatever opponents played, whatever the surfaces. Now while the official rankings certainly do a job in bringing order to the game and do largely reflect players' relative positions, they do not take account of the many nuances which will often have us considering some players to be 'overranked' or 'underranked'.

Tennis Abstact and the bookies do take into account these additional factors, beyond straight ranking points, so will often come up with different orders from the rankings / seedings.

In essence Tennis Abstact and the bookies should be ( and I am sure in general are ) better predictors than the seedings order.

This was the only analysis I could find:

The simplest way to compare rating systems is a metric called accuracy, which counts correct predictions. There were 50 singles matches at the Davis Cup finals, and Elo picked the winner in 36 of them, for an accuracy rating of 72%. The ATP rankings picked the winner (in the sense that the higher-ranked player won the match) in 30 of them, for an accuracy rating of 60%. In this tiny experiment, Elo trounced the official rankings. Elo is also considerably better over the course of the entire season.

A better metric for this purpose is Brier score, which takes into account the confidence of each forecast. We saw earlier that Elo gives Nadal an 81.4% chance of beating Shapovalov. If Nadal ends up winning, 81.4% is a better forecast than, say, 65%, but its a worse forecast than 90%. Brier score takes the squared distance between the forecast (81.4%) and the result (0% or 100%, depending on the winner), and averages those numbers for all forecasted matches. It rewards aggressive forecasts that prove correct, but because it uses squared distance, it severely punishes predictions that are aggressive but wrong.