Practical Chess 2

You are white, to play. Black has just played e7-e5.

Your queen on f4 is attacked. But what's worth more than a queen (apart from you)? Your king - and Black is now also threatening Ba3 mate, having moved their e7 pawn. You can't save the queen and cover the mate at the same time. What should you do?

Well, clearly your king is more important than your queen. Put this position into any engine and it'll tell you to block the mate, for example by playing Kb2.

But wait - that's the "correct" idea, but let's reconsider.

• If you block the mate, you'll be a whole queen down, because Black has definitely noticed they can take your queen - they just moved their pawn to attack it. So you don't have much chance of getting anything from the game.
• Black may well not have played their last move with the mate in mind. Frankly, if the mate wasn't an option - say if white's king was already on b2 - Black may well still have played e7-e5 anyway. It's a central expanding move, gaining a tempo by attacking White's queen. It doesn't hang anything - it's not like it's an unprotected sacrifice to clear the line for the bishop. And it's an obscure mating pattern involving the two bishops with their long-range criss-cross applesauce. It's entirely possible that Black hasn't spotted that Ba3 mate is a possibility.

I would argue that you should move the queen. Sure, 70% of the time you'll lose on the spot to Ba3 mate. But the other 30% gives you more value than the alternative which is trying to salvage something from the game a whole queen down.

The execution

To make this work, move your queen as fast as possible. Don't agonise for 30 seconds over which square it is best placed on - that will just give Black time to spot the mate. Move it somewhere, anywhere, and fast - ideally within 2 seconds! And it's not relevant in this position, but if it was, definitely don't move the queen somewhere where it attacks the bishop, because then the opponent will look around for a place to move the bishop to, and might spot that they can mate you with it!

Does this generalise?

I think this applies at all rating levels, and at all time controls. At higher ratings and longer time controls the chance that Black spots the mate is much higher, but the chance of Black winning a game when they're up a full queen is also much higher in both cases. Moving the queen may only increase your chance of saving the game from something like 1% to 2%, but it's still worth it.

Not convinced?

Not convinced? What if Black's last move was not e7-e5, but e6-e5? In that case they had the opportunity to play the mate last move, and missed it! Surely now if you quickly move your queen you'll be in with a good shot of continuing the game with level material.

This is the sort of advice that you will never find in any chess manual, but it's the kind of practical approach to chess that is important at all levels. The paragraph above shows this in another way: e7-e5 and e6-e5 leave the board in exactly the same position, but the decision of what move White should play as a result is clearly affected. Theoretically, Black's last move is totally irrelevant, but practically, it can mean everything.

Example 2: When attacking

Here's another example showing how you might play the "wrong" move, this time when you're conducting an attack of your own. You are white. Black to play.

You've spotted a tactic: Ne7+ followed by Rh1 pins the queen to the king. You're all set up to play it, but then Black plays Nxb4. What should you play?

You can still go with the tactic, but then you won't have a chance to recapture that knight: 1 Ne7+ Kh7 2 Rh1 Nc6. So you'll have ended up with a queen but given up a rook and a knight - or gained 9 points to 8 in simplest terms. That's good, but not necessarily enough to win.

Or, you can recapture the knight this turn, and hope that Black doesn't spot your tactic on their next turn, letting you still play it. After all, they didn't spot it on the last turn either when they played Nxb4. If that works, you'll be up 9-5 instead of 9-8, which is an overwhelming advantage.

[Note, there is more going on in this position, such as a strong white attack after these move sequences, but the example is just intended to show the principle. Turns out it's hard to create positions that accurately demonstrate a point...]

Conclusion

The general idea applying to both examples here is that you may want to postpone progressing an impactful but more obscure issue (defending against the checkmate, or executing the tactic) in favour of first dealing with a less impactful but more apparent issue (saving your queen, or recapturing the knight), with the expectation that the opponent is unlikely to be aware of the obscure issue. This theme comes up a fair amount in games, and if you focus on what you think the opponent understands, you can give yourself an advantage.

A final simple example

Black plays Bxd4. Oh dear, you've just lost a piece, because if you recapture with Rxd4, Black will play Re1+ and then Rxc1. Therefore, technically by playing Rxd4 you are choosing to trade their d4-bishop for your c1-knight - which is an even trade, so the engine gives this as virtually equal with other moves like Rd2. But in practice, Rxd4 is the best move. You should just quickly play Rxd4, hoping Black doesn't spot Re1+ at all. Maybe they simply wanted to trade bishops.