The following tactics problem, which I suffered some unnecessary blindness on when solving, reminded me forcefully of the necessity of considering sequencing - which is also another way of saying that you need to be able to visualize all of your opponent's responses concretely, and not just your own ideas:
Chess.com tactic problem 40353
Rasovsky - Mikyska
Site: corrs. -
[...] 13...c6 14.¤f6+ gxf6 15.¥d3
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After the (blunder) by Black of 13...c6, breaking down the tactical elements of the position is not hard. Black's last move forces you to think about where the Nd5 can (must) move and with Black's bare kingside, the f6 square immediately suggests itself. The knight then double attacks h7, threatening mate with the queen. Black must therefore take the knight with the g-pawn or lose, in the process leaving the king more vulnerable. However, the White queen itself is still not sufficient to force the a win. What to do?
Then one notices the light-squared bishop, which is in a place where it can move to hit h7. With the g-pawn gone and nothing else on Black's side able to intervene defensively, the mate is assured.
So then why not simply play 14. Bd3 immediately (I thought), since it is just as forcing? After ...g6 in response and then 15. Nf6+, the knight appears to move with the same effect, gaining a tempo on the check and dooming the h7 pawn. But no, in fact the response 15...Qxf6! prevents the combination due to the fact that now both queens are en prise. So only the sequence with the knight moving first can work.
This is just one conceptual example, but many sequencing choices will in fact occur during play. As I've gotten stronger tactically and have been seeing different useful move possibilities in positions, the sequencing part - which I would consider the more sophisticated side of tactics - has become increasingly important. It's certainly good to see those initial tactical ideas, but there remains more work to be done in executing them in my games, including seeing better opportunities in different sequences, for example as shown in Annotated Game #151.