In sports where there are levels of play, a longstanding issue is how to have players playing at the right level. This is a perennial challenge with USTA League play too.
By definition, there will be higher and lower rated players within a given level and while matches will generally be competitive between players at the same level, the higher rated players are going to win more than the lower rated players. For some on the lower end of the range for a level, it is tempting to think "If I were only at the next lower level, I could win more".
The dark side of USTA League is that some players will go out of their way to try to make sure they get bumped down a level so they can win. They may do this by deliberately losing games or matches in order to cause their rating to go down. This is certainly not in the spirit of the rules and unfortunate, but it happens.
In many cases, a player that is right on the margin between levels can get bumped down and their level of play is not so high that there is a major issue with them playing at the lower level. However, it does become a major issue when a player tanks matches so much that someone that can compete and win at the higher level manages to get bumped down to a level where they are clearly at the wrong level.
We'd ideally have a system that can detect when matches are being thrown and compensate accordingly. The challenge is that every player's play varies from match to match so simply having good/bad matches doesn't necessarily indicate suspicious behavior. In generating Estimated Dynamic NTRP Rating Reports, I regularly see players that have a range of 0.5 and a bit more than that is not uncommon, especially when a player is improving during a season.
I recently came across a player that seemingly goes way beyond natural variance from match to match and would seem to be a clear indication of suspicious activity. Here is their chart from their 2013 matches.
We can see that this player has matches rated as high as 4.96 and as low as 3.64. That is a range of 1.32, the largest I've ever seen. A 4.96 is a rating it would be reasonable for a 5.5 rated player to post and a 3.64 could easily be posted by a 3.5. We even see a 3.69 result exactly one week before the 4.96. This is an awfully big range and not what one would normally see from normal variance of play.
We can also see a group of lower rated matches all in September. These matches are from a Fall league that counts towards ratings but does not advance to any National championships and is rumored to be used by some players to manage their ratings down.
Was this player throwing matches to manage their rating? I can't say for sure, I'm just looking at numbers and charts. There could have been factors involved that explain why the results are what they are. I can only say that the wide range is suspicious and makes one go hmmmm.