Note: This post was made in April 2012 but seems to be found by search engines frequently. I am now doing ratings/reports for all USTA League play so contact me if interested in a report or click here to see the latest posts on this blog.
I'm a huge football fan and love doing computer ratings for both the NFL and College Football, but the sport I play the most is tennis and have been playing USTA League Tennis for the past few years.
For those that follow USTA League Tennis, you know that players play at different levels to promote competitive play and the USTA uses a National Tennis Rating Program (NTRP) rating to determine what level a player is at. Levels exist from 1.5 all the way up to 7.0 (in 0.5 increments), but typically league play is at the 2.5 thru 5.0 levels.
Initially, players self rate usually with assistance with a local tennis pro, but there after the USTA computes a Dynamic NTRP nightly throughout the season (self rated players are subject to DQ if their rating increases too much), and then computes an end of year rating which determines the level a player will be at the following year.
The challenge is that the USTA does not publish Dynamic NTRP ratings at all, and the end of year rating is only published to the 0.5 level (e.g. 2.5, 3.0, 3.5, etc.) so one never knows exactly where they fall within their level.
Naturally, I couldn't help but try to determine how all this was calculated and while the USTA does not publish the algorithm, there was enough information out there that I've come up with what I consider a reasonable approximation of the algorithm to the point that I now have what I call an Estimated Dynamic NTRP.
Since I live in the Seattle area, I'm presently only calculating this for the Northwest Washington Area of the Pacific Northwest Section, and I have now published the current ratings with the matches available thru April 16th on the web-site. It is presently just the men's levels from 3.0 thru 4.5. I'll try keep this updated once a week and also include the women's levels soon.
Let me know what you think!
Update: Women's 3.0 and 3.5 now posted too here.
Update: Ratings through April 1st, 2013 posted now here.
Update: Ratings for Southwest Washington now posted too here.
Great work! It seems very accurate and it adds another variable into the discussion of team line ups.
ReplyDeleteKevin,
DeleteI would like for you to review my record and dynamic rating....trying to determine why I didn't get bumped. I went 10-3 for the year and didn't get bumped playing doubles.
Trent, my ratings agree with where you stayed. Contact me if you want a report to see details.
DeleteHey Kevin,
ReplyDeleteYou are a genius! Great job on these dynamic ratings. Can you update the women's numbers??
Thanks!!!
Kevin, I too have done such a thing and would love to compare notes. Please email me at numbersguy55@gmail.com if this sounds interesting.
ReplyDeleteOh Cool! Do you know of anyone who does this in Northwest Ohio?
ReplyDeleteNo, I'm not aware of anyone that does this for other areas other than someone in Texas, but I don't think he publishes his numbers at all. I have designs on doing it nationally for all sections but have more work to do before that will be ready.
DeleteKevin - you must be my long lost twin. I've been dabbling in sports ranking algorithms for 30 years and have applied them to football, baseball, lacrosse, tennis, etc. Just this week, I decided to try to replicate the dynamic NTRP algorithm. If you've already done the work and are willing to share, I would be extremely grateful. I already have all the socres for my local spring league in a MySql DB. My e-mail is cats.commish@gmail.com. By the way, I also run a local (Charlottesville VA) non-USTA league, where we rate players both All-time and past 12 months. Check it out at www.cvilletennis.com.
ReplyDeleteKevin, I'm a USTA tennis player in Seattle and stumbled upon your blog and Google site. I looked myself and some of my friends up. I'm a 3.0 player, and a couple of players who are rated lower than I am on your listing got bumped up to 3.5 in early start ratings. Just wondering what might cause this discrepancy. Thanks.
ReplyDelete@Diane, a few things could cause this.
DeleteFirst, the accuracy of my ratings depends on having a good starting point for the year. I do process back several years so think my starting ratings for 2012 are close, but any variance there will be seen in the current ratings.
Second, the ratings I've posted don't include the local playoffs which were factored in to early start ratings so that is a difference. Did any of the players in question play in local playoffs?
Feel free to e-mail me some specific names (computerratings @ techrunning.com) and I can look into it in more detail. I always like to look at cases like this to see how I can improve my algorithm.
Can you calulate the womens 3.5 level for norcal
ReplyDeleteYes, I've done a lot of reports for individuals and teams in NorCal. E-mail me and I can give you more specifics.
DeleteHey Kevin,
ReplyDeleteHave you happened to do a 2014 rating for New England Eastern Mass? If not, do you do personal NTRP reports for people by request?
Yes, I can do reports on request. See http://sites.google.com/site/computerratings/usta-tennis/example-report for an example report and how to contact me.
DeleteAnd i've actually done some reports for players in Eastern Mass lately and posting some interesting stats on the New England section is on my list to do today.
Thanks Kevin. I emailed my info just now to computerratings@techrunning.com. Is that still the best contact email for you?
Delete