Magnus Carlsen broke into a smile while pondering his 64th move. Vishy Anand grinned back at him, both players revelling in the tension and complexity of their game from the Global Chess League, held in Dubai last month. They were down to less than a minute each, and India’s five-time world champion had just pulled a rabbit out of a hat, with a sacrificial promotion which seemed to ensure a draw by stalemate. Carlsen paused before summoning some even more powerful sorcery, which left Anand only the narrowest chance of escape.

In the first diagram below, 59…b4 looks promising, but 60 Nf1+! wobbles the Black king off its ideal spot, and 60…Kd3 61 cxb4 c3+ 62 Kc1! is a dead end. Carlsen plays a tricky waiting move, eyeing up a role for the bishop in the complications which follow.

Viswanathan Anand-Magnus Carlsen

Global Chess League, Dubai 2023

Black to play, position after 59 a6-a7 (see left diagram). 59…Bd5 60 Nxf5 An attractive idea, which Anand probably expected to lead to a draw. In fact, passive defence was called for: 60 Nf1+ Kd3 61 Ng3! Kd2 with a draw by repetition. If the king chases after the knight, it can be sacrificed on f5 in more favourable circumstances. exf5 61 e6 b4 Obligatory, since the bishop cannot restrain both pawns at once. 62 e7 bxc3+ 63 Ka2 c2 64 a8=Q Deflecting the bishop, thereby avoiding 64 e8=Q c3+ 65 Ka3 c1=Q+ which is hopeless. The deeper purpose is to prepare a beautiful saving resource. Bxa8 65 e8=Q Now if 65…c1=Q 66 Qe3+ secures a draw by stalemate, whether the queen is captured here or on the next move. Undeterred, Carlsen nails down the bishop, hoping to promote later once the stalemate is lifted. Be4 An excellent winning try, though I strongly suspect it was anticipated by Anand. It is astonishing that 65…c3! was the only way to win. 66 Qxa8 c1=Q wins for Black, or after 66 Qd7+ the checks soon run out, e.g. 66 Qd7+ Ke1! 67 Qe7+ Be4 68 Qh4+ Kd1 and Black wins. 66 Qd8+ Bd3 White to play, position after 66…Be4-d3 (see right diagram). The pawn promotion cannot be stopped, but the stalemate idea remains valid, so Anand’s next move prepares for that. 67 Qd4 Now if 67…c1=Q 68 Qe3+ Kc2 69 Qxd3+ cxd3 draws by stalemate once again. But Carlsen has yet another ace up his sleeve – a knight! The Black king will be shielded from checks, and the second passed c-pawn decides the game. For that reason, 67 Qb6! was the only saving move, eyeing up the h6-pawn. If play continues as in the game with 67…c1=N+ 68 Ka3 c3 69 Qxh6 Ne2 70 Qc6 c2 71 h6! White has at least a draw. c1=N+ 68 Ka3 c3 69 Qb6 Ne2 70 Qxh6 c2 White resigns, as the h-pawn is too slow: 71 Qc6 c1=Q+ 72 Qxc1+ Kxc1 73 h6 Nxf4 74 h7 Ng6! wins.