Here’s an exercise for those of you who have nothing else to do on Easter Day. You’re playing a G/75 game against a lower rated opponent. You have 15 minutes or so left on the clock. Black’s just played Ng6xf4, hoping to regain one of his lost pawns. What are your candidate moves? Analyse each one in turn, just as you would in a game, before making your decision. How are you going to finish him off?
Give yourself five minutes for the exercise before reading on.
I reached this position in a recent game. I’d gone into this variation thinking that Nxf4 was not possible because of Qc4, with a double attack on f7 and f4. This seemed fairly obvious to me and it seemed likely that he’d seen this and had something in mind. I then noticed that he had 28.Qc4 Nxh3+ 29.gxf3 Qg3+ followed by Qxh3+ when he seemed to have quite a lot of checks. I started getting scared of the possibility of a perpetual so looked elsewhere. Qe3 sprang to mind: with the queen on the third rank there would be no perpetual. But this gave him time to defend the knight. I considered 28.Qe3 g5 29.g3 to attack the pinned knight again as well as forking the knight and queen, but noticed he could get out of it by 29..Nxh3+ followed by a queen move.
Then inspiration struck. As I couldn’t get my attempts at winning a piece to work, maybe I could play 28.Bxf7+ Kxf7 29. Qc4+ followed by Rxf4 restoring my two pawn advantage. Furthermore, he didn’t seem to have any very safe square for his king after the check. 29..Kf8 obviously lost the queen, 29..Ke7 would leave the king stranded in the middle of the board as well as blocking the rook, and 29..Kg6 also looked pretty exposed.
I made my choice: 28.Bxf7+. On returning home I entered the game into ChessBase, and Houdini promptly told me that I’d completely misanalysed all three variations. I hope you did better.
First of all, looking at Qc4 away from the stress of the competition, it’s clear there’s no perpetual after Nxf3+. For instance, 28.Qc4 Nxh3+ 29.gxh3 Qg3+ 30.Kf1 Qxh3+ 31.Ke2 and the king can run to the queen side. If Black plays Rd8+ when His Majesty reaches the d-file, I could meet this with Rd4. Not too hard, really.
Qc4 would have won easily then, but it turns out that Qe3 is even stronger. Observe: 28.Qe3 g5 29.g3 Nh3+ 30.Kg2 Qh5 (the only queen move to maintain the defence of the knight) 31.g4 (kicking the queen again while opening up the third rank) 31..Qh4 32.Qxh3 with an extra piece. In this variation, even better is 29.e6 fxe6 30.g3 Nh3+ 31.Kg2 Qh5 32.Rxe6 with a winning attack.
After my actual choice of 28.Bxf7+ Kxf7 29.Qc4+, I was correct that 29..Ke7 is too dangerous: 30.Rxf4 Qe1+ 31.Rf1 Qxe5 32.Rf7+ is winning for White. It transpires, though, that, because of the pin on the white rook, the black king can survive after 29..Qg6 30.Rxf4 Qe1+ (I hadn’t seen this at all which is why I’d assumed I’d just be two pawns ahead) 31.Kh2 Qxe5 32.Qd3+ Kh5 (but not Kg5, which does indeed get mated). Houdini can find nothing better for White than trading queens although the resulting rook ending with an extra pawn should be winning.
What happened in the game, then? After 28.Bxf7+, Black didn’t take the bishop, mistakenly thinking, I suppose, that his king didn’t have a safe square after Qc4+. Instead he played Kh8, when I replied 29.Qe3 and won a few moves later.
How should I score your analysis? I’ll award 5 points each for identifying Qc4, Qe3 and Bxf7+ as your candidate moves. (As it happens, Qb4 and Qd4 also win. I don’t think you need to analyse them but you might like to award yourselves a couple of bonus points each for analysing them if it makes you feel happier.) Then 5 points for spotting Nxh3+ after Qc4 and another 5 points for calculating correctly that there’s no perpetual check. 5 points for analysing 28.Qe3 g5 29.g3 Nxh3+ 30.Kg2/h2 Qh5 31.g4 and working out that it wins a piece. Another 5 points if you realised that 29.e6 was even stronger than g3. Up to 5 points (depending on how far you got) for correctly analysing 28.Bxf7+ Kxf7 29.Qc4+ Kg6 30.Rxf4 Qe1+ 31.Kh2 Qxe5 32.Qd3+ Kh5 and realising that other moves were stronger. Then 10 points for choosing Qe3, 8 points for Qc4, Qb4 or Qd4, and 5 points for choosing Bxf7+.
In case you are curious, here’s the complete game. Nothing to be proud of.