Just a little comparison between GLC books. The original website version and one I call random. The latter is basically a collection of GM games with minor modifications (22000 games, 24 plies deep). It outperforms my previous attempts, albeit based on flimsical evidence, which is very encouraging indeed

Program Elo + - Games Score Av.Op. Draws
1 Crafty 19.9 : 2440 62 59 100 58.5 % 2380 27.0 %
2 GLC (random) v3.00 : 2409 69 52 100 52.0 % 2395 32.0 %
3 GLC (org.) 3.00 : 2351 52 60 100 39.5 % 2425 39.0 %
Individual statistics:
1 Crafty 19.9 : 2440 100 (+ 45,= 27,- 28), 58.5 %
GLC (org.) 3.00 : 50 (+ 25,= 17,- 8), 67.0 %
GLC (random) v3.00 : 50 (+ 20,= 10,- 20), 50.0 %
2 GLC (random) v3.00 : 2409 100 (+ 36,= 32,- 32), 52.0 %
GLC (org.) 3.00 : 50 (+ 16,= 22,- 12), 54.0 %
Crafty 19.9 : 50 (+ 20,= 10,- 20), 50.0 %
3 GLC (org.) 3.00 : 2351 100 (+ 20,= 39,- 41), 39.5 %
GLC (random) v3.00 : 50 (+ 12,= 22,- 16), 46.0 %
Crafty 19.9 : 50 (+ 8,= 17,- 25), 33.0 %
Regards,
Mogens