chessflex
Moscow · Apr 1966
Petrosian 12½–11½ Spassky
Petrosian won 12½–11½.
The score gap, game by game: up is Petrosian.
The move that cost the match's loser the most, in a game they lost.
Petrosian v Spassky · 1–0
32... Rc2 by Spassky: chances 50% → 30%
The coach: R2a4 instead (the arrow) — with it, it was about level.
Replay it: Study › Follow a live game › World Championship 1966: Petrosian v Spassky › Game 20
Each line is White's chances move by move, as the coach saw them; above the middle, White is better. The mark is the costliest move.
37 moves · e4 c6 d4 d5 · accuracy Spassky 95.9, Petrosian 96.1
No move cost more than 12%.
50 moves · c4 e6 Nc3 d5 · accuracy Petrosian 93.3, Spassky 94.6
Costliest move: 30... Be6 (Spassky, 49% → 37%)
43 moves · e4 c6 d4 d5 · accuracy Spassky 91.3, Petrosian 91.0
Costliest move: 38... Qe5 (Petrosian, 64% → 49%)
44 moves · c4 e6 g3 d5 · accuracy Petrosian 92.7, Spassky 93.4
No move cost more than 12%.
79 moves · e4 c6 d4 d5 · accuracy Spassky 92.3, Petrosian 91.7
Costliest move: 35. Nd3 (Spassky, 72% → 59%)
15 moves · c4 e6 d4 Nf6 · accuracy Petrosian 94.7, Spassky 95.8
No move cost more than 12%.
43 moves · d4 Nf6 Nf3 e6 · accuracy Spassky 89.7, Petrosian 92.4
Costliest move: 37. Bf1 (Spassky, 27% → 13%)
23 moves · c4 c5 Nf3 Nf6 · accuracy Petrosian 93.1, Spassky 93.1
No move cost more than 12%.
26 moves · e4 c6 d4 d5 · accuracy Spassky 93.1, Petrosian 93.7
No move cost more than 12%.
30 moves · Nf3 Nf6 g3 g6 · accuracy Petrosian 92.2, Spassky 87.2
Costliest move: 23... Nxf4 (Spassky, 50% → 33%)
26 moves · e4 e6 d4 d5 · accuracy Spassky 90.3, Petrosian 91.0
Costliest move: 13. h4 (Spassky, 59% → 46%)
39 moves · Nf3 g6 c4 Bg7 · accuracy Petrosian 89.3, Spassky 90.8
Costliest move: 32. Nxe5 (Petrosian, 67% → 50%)
91 moves · e4 c6 d4 d5 · accuracy Spassky 92.7, Petrosian 91.6
No move cost more than 12%.
57 moves · Nf3 Nf6 g3 b5 · accuracy Petrosian 89.5, Spassky 90.0
Costliest move: 46. Qxe5 (Petrosian, 47% → 32%)
55 moves · e4 c5 Nc3 Nc6 · accuracy Spassky 91.8, Petrosian 89.9
Costliest move: 55... Rc3 (Petrosian, 47% → 3%)
49 moves · d4 g6 e4 Bg7 · accuracy Petrosian 91.2, Spassky 91.6
No move cost more than 12%.
29 moves · e4 c5 Nf3 Nc6 · accuracy Spassky 91.8, Petrosian 93.4
No move cost more than 12%.
33 moves · d4 Nf6 c4 e6 · accuracy Petrosian 89.6, Spassky 91.2
Costliest move: 31. Bb5 (Petrosian, 45% → 25%)
68 moves · e4 e6 d4 d5 · accuracy Spassky 93.5, Petrosian 92.5
No move cost more than 12%.
41 moves · d4 Nf6 c4 e6 · accuracy Petrosian 93.0, Spassky 90.4
Costliest move: 34... Bxh3 (Spassky, 27% → 5%)
39 moves · e4 e6 d4 d5 · accuracy Spassky 93.2, Petrosian 93.1
No move cost more than 12%.
35 moves · d4 b5 e4 Bb7 · accuracy Petrosian 93.7, Spassky 90.3
Costliest move: 35... Qb8 (Spassky, 26% → 6%)
31 moves · e4 e6 d4 d5 · accuracy Spassky 95.0, Petrosian 91.4
Costliest move: 30... Rh2 (Petrosian, 21% → 6%)
77 moves · d4 Nf6 c4 g6 · accuracy Petrosian 89.9, Spassky 90.8
Costliest move: 71. Be1 (Petrosian, 66% → 42%)
Every game of this match is in ChessFlex. Replay it move by move with the coach's three best moves, guess each of Petrosian's moves before you see them, ask the coach why, or take the seat at any moment and play it out against the bots.
In the app: Study › Follow a live game › World Championship 1966: Petrosian v Spassky › Game 1
Part of Study in ChessFlex: one purchase unlocks the coach, Follow a live game and all 53 title matches (on iPhone, try Study free first). Playing the bots is free, with no account and no ads.