Edgar Mamedov vs Sauat Nurgaliyev: game review

20…h6 is a mistake: Black's winning chances go from 44% to 28%.

• White answers 21.Rb7+: the rook reaches the seventh rank, where 2 pawns sit.
• Better was 20…Rae8 (+0.61): the rook takes the open e-file.

Better: 20…Rae8 wins the exchange, picking it up with 21…Bxb7. After 21.Rb7+ Bxb7 22.Bxb7 g5 23.c6+ Ke6, Black comes out two pawns up (+0.61).

21.Rb7+!! A real sacrifice: White gives up material and the engine still rates it best.

• Puts the rook on b7 where it can be taken.
• Black can take, but after 21…Bxb7 22.Bxb7 Bh4 23.c6+ the engine rates it +2.22.
• The rook reaches the seventh rank, where 2 pawns sit.
• Gives check, so the reply is forced.
• 21.Rb7+ invades the seventh rank.
• Black answers 21…Bxb7, winning the exchange.

• The idea: 21.Rb7+!! offers the rook on b7. Taking it gives White the material back and more.
• What White gives up: 21.Rb7+ puts the rook on b7 where it can be taken by the bishop on c6. That's a whole rook on offer.
• If Black takes the rook: 21…Bxb7 is met by 22.Bxb7, taking the bishop on b7. Then 23.c6+ gives check, and 24.Bxg5 takes the bishop on g5. Material is level and White is clearly better (+1.71). This is Black's best try.
• Without the sacrifice: The best move without the sacrifice, 21.Rb4, is clearly weaker (+0.55 against +2.22). Black answers 21…Bg5, pinning the bishop on f4 to the king. That would leave White a little better.

22…Rf8 is a blunder: Black's winning chances go from 26% to 6%.

• White answers 23.Bc7+, which gives check, so the reply is forced.
• Better was 22…Re8 (+2.78): the rook takes the open e-file.

Better: 22…Re8 takes the open e-file. After 23.Rc7 Bg5 24.Rxf7 Bxf4+ 25.Rxf4 Kd7, the bishops are traded and Black is a pawn down (+2.78).

23.Bc7+! The only good move here: every alternative is clearly worse.

• Gives check, so the reply is forced.
• The next best move, 23.h4, would drop White's winning chances from 94% to 77% (+3.26).
• 23.Bc7+ wins a bishop for a rook, picking it up with 25.Rxb7+.
• Sets up a sequence and wins a bishop for a rook once the captures settle, picking it up with 25.Rxb7+.
• Black answers 23…Kd7, leaving White with an isolated pawn on c6.
• After 23…Kd7 24.Bd6+ Bxb7 25.Rxb7+ Ke6 26.Rxe7+ Kf6, White comes out a pawn up (+6.68).

24.Re1!! A real sacrifice: White gives up material and the engine still rates it best.

• Leaves the rook on b7 where it can be taken.
• Taking is too dangerous: Black's best reply is 24…Rg8 25.Bd6 Bxb7 26.Rxe7+ instead (the engine rates it +8.01).
• Pins the bishop on e7 to the king: it can't move at all.
• The rook takes the open e-file, aiming at the bishop on e7.
• 24.Re1 wins a bishop for a rook, picking it up with 26.Rxe7+, and stops …Bxc5.
• Sets up a sequence and wins a bishop for a rook once the captures settle, picking it up with 26.Rxe7+.

• The idea: 24.Re1!! leaves the rook on b7 hanging. Taking it leads to mate.
• What White gives up: The rook on b7 is attacked by the bishop on c6, and 24.Re1 doesn't save it. That's a whole rook on offer.
• If Black takes the rook: 24…Bxb7 is met by 25.Bb5+, and the bishop on a6 gets away. Then 26.Bxc6# is mate.
• Black's best try: Black's best is to leave the rook alone and play 24…Rg8. White answers 25.Bd6, threatening Rbxe7+, winning a bishop. Then 26.Rxe7+ gives check, and 27.Rxb7+ gives check. White ends up a pawn ahead: White is winning (+8.01).
• Why not save the rook first?: Saving it with 24.R7b5, the best way to do that, is clearly weaker (+0.68 against +8.01). Black answers 24…Kd7, threatening …Kxc7, winning a rook. That would leave White a little better.

• Both sides followed opening theory up to 6.Nd2: 11 moves in all, 6 by White and 5 by Black.
• Theory runs out after 6.Nd2: too few games between strong players reached this position to go further.