“When you see a good move, look for a better one.”
Often attributed to Emanuel Lasker.
But this quote predates him, going back at least to 1878.
“Still flying at high game, in accordance to with the rule, ‘When you see a good move look out for a better’. ” – The Chess Player’s Chronicle, January 1878, pg. 31.
Nevertheless, this is still a good rule to follow, and not just in chess.
But, since this a chess blog, we’ll stick with chess.
Years ago, I was watching a young person playing a tournament game. He was White and had an overwhelming position. The following diagram is a close approximation of the position I recollect.
It is White to move.
Now this young person played 1.Qd5+ and Black responded with his best move; 1…Kh8. White continued with 2.Qxa5.
After the game ended, I asked this young person why he took the pawn. He asked me if what he played was a bad move. I told him it was not a bad move; I was just curious. He replied that he knew that a Rook and Queen would mate the Black.
I then asked him if he could mate with just a Queen. He said he could, but he saw the win with the Rook and Queen, and seeing nothing wrong with it, went with the idea.
White, of course, could win the game outright with 1.Qg6+. If Black plays 1…Kf8, then White mates with 2.Qf7#. And if Black moves his king to h8, then White mates with 2.Qg7#.
It’s a malady we all seem to have.
Let’s jump ahead a few decades.
Chess.com, Mar. 8 2020
White just played 21.Bb4 and Black’s queen is in trouble.
Black apparently panicked and played 21…Qxa2? (he would have lessened the danger by playing 21…Rxd1).
And White, seeing a win and a possible mate, responded instantly with 22.Rxd8! Rxd8 23.Qxd8+ Kg7 24.Bf8+ Kg8 25.Bh6#. 1-0 But this is not the end of the story. For White could have played the mate a move earlier with 24.Qf8#. Why didn’t I play that move? Well, you see I saw the mate, and then stopped looking.