Manual de Chess King 2015 | Page 78

PART 1 • When it comes to computer chess, “handicap” is not a nasty word The Elo rating slider – the “old standby” which is a part of nearly every commercial software program released in the last decade or so. The software offers a slider which you can adjust to make the program stronger or weaker; moving the slider also displays the approximate rating at which the program will play. These numbers are rarely exact, since a rating is just a benchmark of your expected performance against a specific opponent, based on your prior performance within a closed pool of players. Translated into English, that means that you as a player can actually have widely different ratings at the same time: one for your real life tournament games, one for correspondence games, one assigned by playing rated games against a chess computer, and one for every single online chess site at which you compete, and these may or may not even be close to each other. So any rating offered by a chess program, whether assigned to a “virtual” personality or the position of a rating slider, is an approximation at best. We'll be discussing this feature a bit later in this chapter, because it's almost a “universal” feature and is very useful for the average player. Quite a few chess programs also allow you to adjust the engine's play according to specific criteria, such as aggressiveness, defensiveness, King safety, and central control, as well as to tweak the engine so that it might prefer certain chess openings or move some pieces more than others. I've used these features successfully in the past to roughly simulate the play of a few of my real life chess club opponents, but it's largely a matter of trial and error, and you have to be dang near a cross between Claude Shannon and Mikhail Botvinnik to get it just right on the first try. But I do encourage you to look for and play around with such features in your favorite chess program, though I won't be discussing them any further in this book. 78 chessking.com