Grenv and others -

I am quite familiar with the ratings system that is used here at Brain King. I'm sure that a better rating system can be devised for A FEW of the games here, but for a SINGLE rating system, the one that we have works quite well for MOST games. Let me explain.

In games with a high degree of luck such as Backgammon, the stronger players will 'float' towards the top ratings in a much slower fashion then in 100% skill-based games like Chess. Also the difference between the rating of a top player and a beginner will be MUCH smaller, simply due to the luck factor. That is because the ratings difference effectively reflects an approximate % of time that a player can be expected to beat another player. For the U.S. Chess ratings system that is used here, if a player is rated 200 points above another, he can expect to win 75% of the time. 400 points difference is 90% and 800 points difference is 99%.

It is NOT an advantage to play a higher rated player OR a lower rated player UNLESS you KNOW that player to be over or under-rated. This can happen when one player plays just 2 or 3 other players ONLY over and over.

Of course you will gain more by beating a higher rated player and less for beating a lower rated player, but that is because it is harder to beat them. I'll give an example. Let's say in Backgammon with the doubling cube, you would normally beat another player 90% of the time. That means that you would gain 3.2 points for winning and lose 28.8 points for losing (if both players have established ratings). But because the doubling cube is NOT used, you are only able to beat them 75% of the time, due to the luck factor. That means that you would gain 8 points for winning but lose 24 points for losing. What that means is that your rating will eventually settle at about 200 points higher than the other player without the cube, whereas it would be 400 higher WITH the cube.

So the fact that there is luck involved just means that there will be more upsets in the tournaments, but does NOT mean that it is an advantage or a disadvantage to play a high or low rated player. It also means that the range of ratings from the top player to the lowest player will be much smaller than in 100% skill-based games.


Gary