Game Set Match uses the
Elo rating system
to compute singles and doubles ratings.
The Elo system was originally invented as an improved chess rating system
but is also used as a rating system for multiplayer competition in a number
of video games, association football, gridiron football, basketball, Major
League Baseball and other games.
We believe it is a much better system for assessing tennis skill than the
standard of NTRP ratings. The system is self correcting and ratings
continually become more accurate the more you play on Game Set Match.