Tuesday, September 25, 2012

A big chess win

Last week I earned the highest-rated win of my online chess career in a three-days-per-move game that lasted for four months. My opponent was a Carolina alumnus and football fan who was rated as an expert at 2027 before he fell. My rating was 1579. Any pairing separated by more than 200 points is supposed to be instructional and noncompetitive. But when he made an early mistake that cost him a pawn, I stopped scheduling other games to focus on clinging to my small material lead.

I would not have bothered to post this here, but chess.com had a nifty gadget that displayed the game and allowed me to narrate. My comments appear in the box below the board after certain moves.

What a thrill.


Nov. 20, 2012 addendum: I found a post on the North Carolina Chess Association's blog that correlates rating gaps to match and game results probabilities. I also found a page at ascotti.org that, according to the NCCA post, is not quite what it purports to be. 

My interpretation of the post and page is that I had a 3 percent chance of winning, a 6 percent chance of drawing, and a 91 percent chance of losing. These probabilities are based on the 448-point rating gap that existed at the end of this game. The rating gap at the beginning of the game would have been a better predictor, but I do not know what it was. I think it was smaller.

My opponent's rating has since fallen to 1906, which puts our current rating gap at 291. If we played again today, my odds would improve to a 7.5 percent chance of winning, a 15 percent chance of drawing, and only a 77.5 percent chance of losing. That is rosier but still daunting.