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.