Stockfish rates moves by chasing them down a game tree and evaluating positions. I can imagine several heuristics for a "non-obvious move here" buzzer based on that architecture:
- Hidden gem: The best move has similar value to others if exploring a few moves, but becomes clearly better at depth [n].
- Trap: There is a move that has similar value to others on shallow exploration, but offers opponent a checkmate at depth [n]
- Material exchange: The best move involves a major material loss in the first few moves.
I would love to see these tested in practice, but it seems very plausible to me that some combination of them could make a very useful one-bit (erm, one-butt?) signal.
- Hidden gem: The best move has similar value to others if exploring a few moves, but becomes clearly better at depth [n]. - Trap: There is a move that has similar value to others on shallow exploration, but offers opponent a checkmate at depth [n] - Material exchange: The best move involves a major material loss in the first few moves.
I would love to see these tested in practice, but it seems very plausible to me that some combination of them could make a very useful one-bit (erm, one-butt?) signal.