How Koga decides
Definition A quiet move that rescues a losing position
- We are already clearly worse — losing by more than about half a pawn before the move is played.
- The move is a quiet defensive resource: it is NOT a capture and it does NOT give check.
- Despite being so quiet, the move turns the evaluation around — it improves our standing by at least a full pawn.
- When a calm, non-forcing move recovers that much ground from a losing position, we flag it as a counter-tactic: a hidden defensive idea that the position rested on.
Conditions When we do NOT call it a counter-tactic
- Not losing — if we were not already clearly worse beforehand, an improving move is just good play, not a saving counter-tactic.
- A capture — if the move grabs a piece, the gain is explained by the material won, so it is handled as the relevant capture tactic instead.
- A check — checks are forcing moves; a saving check is recognised as a counter-threat (see below), not as this quiet category.
- Too small a swing — the move must recover at least a full pawn of evaluation. A small improvement does not qualify.
Contrast How this differs from Counter Threat
- Counter Threat is recognised geometrically and by force: the enemy is threatening to win one of our pieces, and our reply is FORCING — it gives check, attacks an enemy piece worth a knight or more, or leads to a forced mate in the line. Counter Threat never looks at the evaluation.
- Counter Tactics is the mirror image: the move is deliberately QUIET — no capture, no check, no forcing line — and we recognise it purely from the evaluation swing, by the fact that a losing position is suddenly held.
- So the same defensive intent is split by how it is delivered: by a forcing blow (Counter Threat) or by a calm, quiet resource that the engine's evaluation reveals (Counter Tactics).
Test positions (the examples that guard against regressions)