Manual de Chess King 2015 | Page 113

PART 1 • Opening choices at a glance games (997,888), and gets the percentage of points which Black won in all games in the database in which the position after 1.e4 c5 occurred. The big thing you need to remember is that the higher the actual percentage is, the better that move did as far as the final game results go. High percentages are good; low percentages are bad. But (and this is a big “but”) you can't just blindly follow the numbers in an opening tree! If a move was played thousands of times successfully over many decades, it'll have a high percentage. But if just one reply to that move, discovered last year, is a total killer which destroys that variation so that no one will ever play it again, it'll still have a high success percentage in a chess tree because it was played so often before that new move which destroys it (chess players say “refutes it”) was discovered. So the rule of thumb is to look at the numbers, use them as a rough guide, but always, always, always think for yourself! Chess King also offers an additional column, called the “score”. That's an evaluation of the position as generated by a chess engine. This is a useful additional guidepost. Even though 1...c5 earns nearly half of the available points when it's played (it succeeds 49% of the time), it's by no means a “killer move” for Black; in a chess engine's opinion, 1...c5 results in a position which favors White by 15/100ths of a pawn, by no means a major advantage for either player. Remember our Caro-Kann position from the previous chapter? 1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. h4 h6 7. Nf3 Nd7 8. h5 Bh7 9. Bd3 Bxd3 10. Qxd3 Qc7 11. Bd2 113 chessking.com