I don't quite understand this. I like playing chess, and I'm working to improve, but I still am likely very much a novice.

Anyway, I played a game where I won in 9 moves, but I'm curious why the engine suggested the "best move" it did.

My game was as follows (I was playing as white):

[fen ""]

1. e4 e5 2. d4 Nf6 3. dxe5 Nxe4 4. Qe2 Bb4+ 5. c3 Bc5 6. Qxe4 O-O 7. Be3 b6 8. Bd3 Bb7 9. Qxh7#

The engine suggested during analysis that a better move than Bd3 (move 8) was Qxa8.

I acknowledge I still have much to learn about the game, strategy, etc. But I'm curious why this is the better move. After Bd3 I'm easily set up for a checkmate if the opponent doesn't do g6.

Does Qxa8 set up something I don't realize? Am I missing a line? What's going on there?

  • 1
    The mate threat is irrelevant because it is easily defended. The machine is thinking (as you should) about what happens if Black does do g6, and whether your position after Qxa8 is better with the bishop on d3 or f1.
    – bof
    Oct 20, 2019 at 6:46
  • Thank you. How would the position be better on f1, though?
    – M1976
    Oct 20, 2019 at 11:14
  • Maybe your engine was looking at lines like 8.Bd3 g6 9.Qxa8 Bxe3 10.Qxb8 Qg5 where it looks like the bishop would be better employed on f1 guarding its own g2 than on d3 biting uselessly on g6. But I don't know, I'm just a patzer, the people who answer questions here are experts or masters.
    – bof
    Oct 20, 2019 at 11:59
  • Don't use engines for these types of inbalanced positions. Their evaluation is pretty meaningless
    – David
    Oct 20, 2019 at 18:14

3 Answers 3


On my quad-core running Stockfish 10, the evals are very close, but Bd3 is preferred, and to me, I agree since you develop a piece with tempo, black defends the mate, and then you still take on a8 winning.

It is really about the same, but Bd3 is slightly better on my engine.

Basically, your intuition is right, and maybe your engine or computer are not as strong...or maybe even mine is not.

  • 2
    I was using the "non pay" engine that comes with chess.com to analyze the game. It's a "quick analysis".
    – M1976
    Oct 20, 2019 at 11:15

I'll go along with Qxa8 wins a rook right now, as opposed to one move later. But you're about to discover something about chess engines, which will be useful later on, no matter how good you get at chess.

The line the intrigues me is 8. Qxa8 Nc6 with the idea of trapping the Q out of play for a while. What can Black get from that? So perhaps at this point, when the engine suggests Qxa8, explore what it is the engine sees by going ahead and playing it and then playing a response that might make sense, and see what the computer wants to continue with.

Then, once you think you've milked everything you can learn about the computer's suggestion, go back to the position and make your move (8.Bd3) and see what the computer wants to play against it. (8. ... g6 isn't necessarily the only response you'll want to explore, btw. You could use your engine to explore the ramifications of 8. ... f5 while you're at it; will the king flight through f7 work well enough to save the rook? I'll leave that as a fun question for you to answer on your own.)

While you do that, you may discover than one of the most useful things about an engine is they never get tired of playing different moves from a position. So when you get to a position where you disagree with the engine, you can play the position out multiple times with multiple responses; the engine will patiently show you what it's seeing for each of those lines. And the more different continuations you play out, the more you will understand what's going on in the position, and the better you will know what to play when positions similar to it arise in your future games.

The object, after all, is not to learn how the engine works, but to understand chess; and the engine can be a useful tool for that. Use it to explore the position and you can find out.

  1. Qxa8 wins a rook and is almost certainly a won game for white.

  2. Bd3 threatens mate but is easily countered.

Always assume your opponent makes the best reply. Making a move and hoping your opponent doesn't see the reply is "hope chess" and won't get you very far.

  • 2
    8.Bd3 is not "easily countered". Not at less big a price than a rook, so even against best play by Black (8.Bd3 g6 9.Qxa8) the gain for White is as big as after 8.Qxa8.
    – Evargalo
    Oct 21, 2019 at 14:08
  • @Evargalo- The mate threat is easily countered by g6. If I'm wrong, show me how white still mates after g6.
    – Savage47
    Oct 22, 2019 at 0:11
  • 1
    The question is not whether White has a forced mate after 8.Bd3. He doesn't. But he wins a full rook. When you compare 8.Qa8 and 8.Bd3, you should use the same standard for both. You cannot say that the former is successful because it wins a rook (but doesn't mate fast) and that the latter fails because it doesn't mate fast (but wins a rook).
    – Evargalo
    Oct 22, 2019 at 5:39

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