Tuesday, May 8, 2012

Updated Men's Estimated NTRP ratings through 5/6/2012 - Some statistics

The new men's Estimated NTRP rating through 5/6 have been posted to the site.

At this point in the year, there have been enough matches that we can look at a few interesting statistics.

First, looking at the average rating by NTRP rating we can see the following:

  • NTRP 2.5 - 2.27 (slightly above the 2.25 that is the expected average in the middle of the range)
  • NTRP 3.0 - 2.72 (slightly below the 2.75 midpoint)
  • NTRP 3.5 - 3.20 (a bit below the 3.25 midpoint)
  • NTRP 4.0 - 3.65 (a bit more below the 3.75 midpoint)
  • NTRP 4.5 - 4.17 (also a bit below the 4.25 midpoint)
  • NTRP 5.0 - 4.64 (also a bit below the 4.75 midpoint)
It is interesting that generally my estimated NTRP for a group is a bit below the expected midpoint.  Now, to be fair, these averages are virtually unchanged from the start of the year, so this is more an artifact of those starting ratings than anything calculated this year, and I also don't know that one should expect the average to actually be at the midpoint.  Still interesting to look at.

On a personal note and to get a glimpse into how the ratings work, I played two USTA matches since the 4/30 ratings, a 6-0, 6-4 loss in doubles at 4.0 and a 6-0, 6-4 win in singles at 3.5.  A simple observation would be that the scores cancel each other out but it doesn't work that way, as it is the score and the opponent that matters.  And in doubles, who your partner is matters too.

In my case, the 4.0 opponents were pretty good so the loss didn't hurt that much.  Additionally, my last match, a 6-2, 6-2 win in doubles at 3.5 over weak opponents which had pulled my rating down didn't count as much now and my rating actually went up after the loss.  Then the singles win at 3.5 was over a decent player and my rating went up a bit more.

The lesson learned is that it isn't just winning or losing that matters to your rating, it doesn't even matter which court you play, rather it is who you play with (in doubles), who you specifically play against and their rating, and the total games won/lost that determines your rating.

10 comments:

  1. Great website! I did a generic google and found it yesterday.

    I looked at a variety of players and it seems the wildcard is how many years you have played and what your rating was for the previous 4 years (read this somewhere it figures in). For example, two players had different movement in rating and the only difference was one was a 3.0 for 3 years and the other was for 4 years. 4 year player moved up and the 3 year player stayed the same. Maybe another column or figure where it takes this into consideration?

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  2. How many years you have played or the duration your rating has been at a given level only impacts your rating indirectly and in a very small way. Every time you play a match, a rating is for that match is calculated based on the score, your partner's rating (if doubles), and the opponent(s) ratings, and that match rating is averaged with your last three dynamic ratings to calculate your new rating.

    So, the history does have an effect, but in a very diminishing way. And the match results from prior years will only have much of an impact if you play very few matches each year.

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  3. Thanks Kevin, that makes sense.

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  4. I understand there's a threshold where you can automatically successfully appeal. Any idea where that falls? Maybe .05 or .1?

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  5. Roger, that is what I've heard too, but don't know specifics and the threshold may change from year to year.

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  6. Ok, another question after looking at the ratings. When you started this a couple of years ago, how did you start everyone? For example, 3.5er would have started their rating at 3.25 and you do that now with the self raters?

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  7. Yes, if there is no rating, a player is started in the middle of their range. As I get more data, I may change this to do what I believe the real NTRP does which is to not start them anywhere but have their rating get calculated from their first few matches.

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  8. I really wonder what motivates a particular club on the eastside/Seattle that always find players to self rate at a lower level than their actual rating. For example, one girl just out of college, rated a 3.5 even though she was clearly a 4.0 with her skills. This was clearly demonstrated during the playoffs. And the fact she got 6th in the Washington State tourney in 2008 High School which would have made her a 4.0 by the USTA guidelines. However the coach rated her a 3.5. Then, only play her a couple of matches during the year so her self rating error isn't identified and she is DQ'd. Is it really that much fun to do this knowing you are cheating to win? You wonder if the USTA would implement a program where you had to play a minimum number of matches (say 5?) to be able to do the playoffs?

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  9. @Anonymous Great questions, but I can't really speak to the motivations of others. I know I play USTA League to have friendly competition and value the opportunity to play opponents that play at a similar level that I do so that matches are competitive.

    The USTA does have minimums to get to playoffs, I believe it is 2 regular season matches, but it isn't the 5 you ask for. And even at 5, someone that wants to can make sure matches are close enough as to avoid getting DQs so for someone trying to manipulate the system, they would still do so. I would hope the USTA does catch and punish folks that do violate self rating rules though.

    I actually struggled with deciding to post the ratings I have as they do equip system manipulators with more information so that they know when they may have strikes or what level an opponent may be so how close they need to keep a match to avoid strikes. But my hope is that the majority of people that visit the site are simply interested in seeing the ratings and perhaps using them to determine who to run out in a match, but once the ball is in play, go out and play their best and let the results and resulting ratings fall where they may.

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  10. Hey Kevin I am in the same boat you are that I play USTA to have fun against players rated at my similiar level. I love getting beat by someone who has similiar skills and has a great day. I hate getting slaughtered by someone "ranked" at my level that is a cheater. I appreciate the site and the work you do on it as I watch my ranking move up and down.

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