Saturday, May 10, 2014

I've gone winless (0-7) in USTA League play and my Dynamic NTRP rating has gone up?!

I just created an Estimated Dynamic NTRP Rating Report for someone that had gone 0-7 thus far this year, all at level and not playing up, and was wondering if they were at risk of being bumped down.  The report showed this was not the case and in fact their rating had gone up!  How can this be?

Let's look at the report.

Current NTRP: 4.0C
Estimated DNTRP: 3.66
Match Record: 0-7
Singles Record: -
Doubles Record: 0-7
Sets Won-Lost: 3-14
Games Won-Lost: 59-79
Best Match Result: 4.05 on 3/31/14
Worst Match Result: 3.45 on 3/16/14
Highest Estimated DNTRP: 3.8 on 3/31/14
Lowest Estimated DNTRP: 3.57 on 10/28/13
Singles Average Match Rating: -
Doubles Average Match Rating: 3.72

The winless record and losing 14 of 17 sets would seem to indicate they aren't doing that well, but the rating has gone up about a tenth and they've had three matches rated over 3.8 and one over 4.0!  On the surface, this makes no sense perhaps, but trust me, there is a reason.

The 2/1 match was a match tie-break loss played with a lower-half 4.0 against an upper half 4.0 and a 4.0 rated above 4.0 and likely to get bumped up.  So they were supposed to lose fairly easily and the close win was better than expected and a good result.

The 3/10 match was played with the same partner against two strong 4.0s and also went to a match tie-break, so same reasoning.

The 3/31 match was played with a 3.5 playing up against two very strong 4.0s and again went to a match tie-break.  Getting such a close result with a lower rated partner is a great way to generate a big match rating.

So remember, the NTRP algorithm doesn't really pay attention to win/loss record, instead it looks at the specifics of the ratings of the players involved in the match, the score, and how close the score is to what was expected.  Do better than expected, you get a big match rating.  Do worse, and the match rating could be lower.