The title "Human Chess is a chess variant where playing the top engine move is forbidden" kinda suggests that the top move just isn't available to the player.
However, the thought you had, and similar ones, are very much the intentional side-effect of the rules. The only way to win the game, as stated, is forcing your opponent to make the top engine move. Or, of course, correctly claim that your opponent made such a move (even though it wasn't forced). Or, having your opponent make the incorrect claim about your move.
So, it isn't necessarily "playing good chess". Though, I must say, I'm not qualified to have any good idea of what it would mean to be good at this game. It definitely helps to be good at chess, and have a good command of what are the correct engine moves. Especially since you lose if you incorrectly claim a position and opponent move was "the top engine line".
I suppose most would reduce this to leaving the opponent to only one legal move. In which case, the problem is is trivial. But, after move 2? You need to know most opening lines, and probably play intentionally bad in many situations.
Hm, this is cooler the more I think about it.
Imagine intentionally setting up material sacrifice with a resulting choice of multiple moves for the opponent to capitalize. If you can correctly evaluate the best computer move, you have a strong advantage. If it is not obvious, then the opponent might not dare to gamble the challenge.
Has Hikaru tried this in one of his streams? I'm certain he would have a blast.
The only thing about this that doesn't "spark joy" are the ambiguous practical implementations.
- Which engine? This matters a lot.
- How do you define the computational cut-off? CPU-minutes? Move depth? Etc. Not necessarily a simple problem.
- The rule "When multiple moves have the top score, they are all top moves". Needs a specific score evaluation delta for grouping "top moves".
All of these could rather simply be resolved if it isn't very important... might even add some uncertainty to it, for fun. Like, say: 1. Stockfish 15. 2. Allow the computer whatever resources it has available, 1 minute, and play some drum roll sample. 3. Pawn-evlauation of 0.05.