Stockfish 19 against SF 18 with 3 books and one bookless

[Jouni]

Elo gain one core 60 + 0.6 after 200 games:

UHO +44
HERT +9
8MVS +14
NOBOOK +5

Without book SF19 won 3 games one even with black. Here SF18 has rare tactical blunder

[pgn]
[Event "No book"]
[Site "?"]
[Date "2026.09.08"]
[Round "42"]
[White "Stockfish19"]
[Black "Stockfish18"]
[Result "1-0"]
[ECO "C67"]
[PlyCount "124"]
[EventDate "2026.??.??"]
[TimeControl "40"]

1. e4 {[%eval 30,20] 1.2s} e5 {[%eval -36,20] 1.9s} 2. Nf3 {[%eval 27,21] 0.58s
} Nc6 {[%eval -33,19] 0.71s} 3. Bb5 {[%eval 29,22] 0.85s} Nf6 {[%eval -26,19]
0.55s} 4. O-O {[%eval 16,25] 2.5s} Nxe4 {[%eval -34,20] 1.1s} 5. Re1 {[%eval
12,21] 0.67s} Nd6 {[%eval -33,20] 0.69s} 6. Nxe5 {[%eval 25,22] 0.69s} Be7 {
[%eval -32,20] 0.92s} 7. Bf1 {[%eval 16,24] 1.1s} Nxe5 {[%eval -31,20] 0.89s}
8. Rxe5 {[%eval 15,23] 0.98s} O-O {[%eval -20,19] 0.78s} 9. d4 {[%eval 14,22]
0.74s} Bf6 {[%eval -25,19] 0.93s} 10. Re1 {[%eval 13,22] 1.1s} Re8 {[%eval -22,
19] 0.74s} 11. Bf4 {[%eval 16,24] 0.80s} Rxe1 {[%eval -26,20] 0.72s} 12. Qxe1 {
[%eval 10,20] 0.74s} Ne8 {[%eval -24,18] 0.67s} 13. Qe3 {[%eval 12,22] 0.78s}
d5 {[%eval -25,20] 0.96s} 14. Nd2 {[%eval 8,21] 1.0s} Bf5 {[%eval -20,20] 1.1s}
15. c3 {[%eval 6,22] 0.74s} Nd6 {[%eval -15,19] 0.54s} 16. Nf3 {[%eval 10,28]
6.1s} a5 {[%eval -11,20] 1.3s} 17. Re1 {[%eval 7,19] 0.49s} c6 {[%eval -15,24]
3.5s} 18. Be5 {[%eval 9,25] 3.8s} Be4 {[%eval -18,16] 0.57s} 19. g3 {[%eval 14,
20] 0.54s} a4 {[%eval -16,22] 2.2s} 20. h4 {[%eval 15,19] 0.68s} Be7 {[%eval
-20,19] 0.66s} 21. Bf4 {[%eval 12,21] 0.75s} Bf8 {[%eval -17,17] 0.74s} 22. h5
{[%eval 8,20] 0.85s} Qb6 {[%eval 1,20] 0.61s} 23. Ng5 {[%eval 60,22] 3.7s} Qxb2
{[%eval -80,21] 2.5s} 24. Bxd6 {[%eval 66,17] 0.95s} Bxd6 {[%eval -85,18] 1.0s}
25. f3 {[%eval 59,17] 2.0s} h6 {[%eval -85,19] 1.1s} 26. Nxf7 {[%eval 275,19]
2.0s} Rf8 {[%eval -233,26] 6.4s} 27. Nxd6 {[%eval 295,18] 0.52s} Rxf3 {[%eval
-245,18] 1.1s} 28. Qe2 {[%eval 315,20] 0.67s} Rxg3+ {[%eval -253,19] 1.6s} 29.
Kh2 {[%eval 354,18] 0.79s} Qxe2+ {[%eval -255,17] 0.86s} 30. Rxe2 {[%eval 359,
19] 0.97s} Rxc3 {[%eval -262,19] 0.64s} 31. Nxe4 {[%eval 317,18] 1.3s} dxe4 {
[%eval -257,17] 0.63s} 32. Bg2 {[%eval 322,18] 0.53s} Kf7 {[%eval -261,21] 1.2s
} 33. Bxe4 {[%eval 361,18] 0.71s} Kf6 {[%eval -258,21] 1.3s} 34. Kg1 {[%eval
355,19] 0.65s} Rc4 {[%eval -262,20] 1.6s} 35. Rd2 {[%eval 350,20] 0.62s} b5 {
[%eval -269,17] 0.58s} 36. Kf2 {[%eval 404,20] 0.79s} Ke7 {[%eval -338,28] 8.2s
} 37. Rc2 {[%eval 430,21] 2.0s} Rxd4 {[%eval -338,21] 1.2s} 38. Ke3 {[%eval
458,19] 0.75s} Rd1 {[%eval -354,21] 2.1s} 39. Bxc6 {[%eval 501,20] 0.82s} Rb1 {
[%eval -340,16] 0.15s} 40. Rd2 {[%eval 500,19] 0.76s} Rg1 {[%eval -368,20] 0.
90s} 41. Bxb5 {[%eval 502,19] 1.3s} Rg5 {[%eval -367,14] 0.073s} 42. Be2 {
[%eval 525,19] 0.51s} g6 {[%eval -366,15] 0.087s} 43. hxg6 {[%eval 526,20] 0.
57s} Rxg6 {[%eval -367,17] 0.12s} 44. Bd1 {[%eval 536,17] 0.65s} a3 {[%eval
-359,17] 0.42s} 45. Rh2 {[%eval 540,23] 3.4s} Re6+ {[%eval -364,18] 0.65s} 46.
Kd2 {[%eval 525,21] 1.8s} Rd6+ {[%eval -366,14] 0.29s} 47. Kc2 {[%eval 517,18]
0.41s} Kf7 {[%eval -378,19] 0.61s} 48. Rh3 {[%eval 530,22] 1.6s} Kg6 {[%eval
-383,17] 0.28s} 49. Bh5+ {[%eval 527,18] 0.34s} Kg5 {[%eval -379,18] 0.15s} 50.
Be2 {[%eval 527,19] 0.11s} Re6 {[%eval -392,23] 1.2s} 51. Kd2 {[%eval 535,18]
0.30s} Rb6 {[%eval -386,19] 0.59s} 52. Rxa3 {[%eval 527,19] 0.29s} Rb2+ {
[%eval -388,19] 0.29s} 53. Ke3 {[%eval 534,19] 0.54s} Kf6 {[%eval -401,21] 0.
52s} 54. Ra5 {[%eval 546,20] 0.25s} Rb8 {[%eval -404,18] 0.30s} 55. Ra6+ {
[%eval 540,21] 1.3s} Kg7 {[%eval -415,20] 0.50s} 56. Kd4 {[%eval 575,20] 0.57s}
Rd8+ {[%eval -414,18] 0.26s} 57. Kc5 {[%eval 573,15] 0.051s} Rh8 {[%eval -423,
20] 0.54s} 58. Bb5 {[%eval 624,24] 0.27s} Kf7 {[%eval -467,18] 0.42s} 59. Ra3 {
[%eval 632,18] 0.078s} h5 {[%eval -505,18] 0.40s} 60. Rh3 {[%eval 637,22] 0.22s
} h4 {[%eval -507,16] 0.36s} 61. a4 {[%eval 640,16] 0.14s} Ke6 {[%eval -551,18]
0.44s} 62. a5 {[%eval 664,23] 0.18s} Kf5 {[%eval -633,18] 0.41s, White wins by
adjudication} 1-0

[/pgn]