Checkers Openings

Expert checkers players, past and present, say that some openings are stronger than others, although with "best play" by both sides all lead to drawn games per the University of Alberta study using its world-famous Chinook checkers program. (This conclusion was anticipated because of the large numbers of draws between expert players.) From strongest to weakest, the rankings are 11-15, 9-14, 11-16, 10-15, 10-14, 12-16, 9-13. (Some authors consider 11-16 and 10-15 to be of equal strength.) The purpose of this study is to corroborate (or refute) these rankings by determining which lines of play in each opening lead to draws rather than losses, assuming best play by both sides. The openings with the most drawing lines are the strongest while those with the fewest drawing lines are the weakest. An additional study corroborates (or refutes) the rankings of the replies to the reputed strongest checkers opening, 11-15. The replies 22-18, 23-18 and 23-19 are strongest, 22-17 is adequate, and 21-17, 24-19, and 24-20 are inferior according to the experts. Again, however, with best play by both sides, all end in draws.

Since the number of possible lines of play in the games is extremely large, a simplifying method is used to arrive at the results: (1) The most popular lines of play used by Internet Checkers opponents from around the world against the author are analyzed before those of the least popular lines because this considerable and varied playing experience leads to the statistical conclusion that the least popular lines lead to few draws. (2) The one best reply by the author to each opponent move is provided by the checkers programs Chinook or Cake, thus eliminating analyses of weaker replies, which would have no more (and more likely, fewer) drawing lines. Using these preferred replies, these 3-move openings that are known to lose (with "best play") from computer and human play receive minimal analysis in this study: 9-13 22-18 5-9; 9-13 22-18 13-17; 9-14 22-18 12-16; 9-14 22-18 14-17; 10-14 24-19 9-13; 10-14 24-19 11-15; 10-14 24-19 14-17; 10-15 21-17 9-14; 10-15 21-17 12-16; 10-15 21-17 15-19; 11-16 22-18 10-15; 12-16 24-20 9-14; 12-16 24-20 10-14. (3) A game is terminated when after 14 to 18 moves by the author v. opponents (which usually removes about half of the checkers) the remaining moves are played between the Chinook and Cake computers. (4) Relative complexity of the positions ("landings") between openings is ignored. Using these simplifications, those lines that result in a draw for each opening can be determined and counted. The openings with the highest number of drawing lines are the strongest and those with the lowest number of drawing lines are the weakest.

This study is in process and no conclusions are currently available.

Note: Black always moves first. Captures are forced. Moves are denoted by numbers, which refer to the standard checker board where Black is at the top and White is at the bottom. Black's single corner is 4 (at his left) while White's single corner is 29 (at his left). Black's double corner is 1 and 5 while White's double corner is 28 & 32.