Not currently surfaced in the X-ray Coach. Koga's bombardinio detector is currently disabled in the live classifier (commented out of the dispatch), so it is never sent to the X-ray Coach.
How Koga decides
Definition A piece sacrifice that forces mate
- Bombardinio is a sacrifice: we deliberately move a piece worth at least a knight onto a square where an enemy piece can capture it, and the forcing line that follows ends in checkmate.
- We only look at it once the moved piece is actually offered — there must be an enemy piece that can take it on the square it just landed on. A move that gives nothing away is not a bombardinio.
- A captured pawn is never enough to qualify as the offer: the piece we throw in must itself be worth at least a knight.
The mate The line must end in checkmate
- We follow the forcing line in which the opponent accepts — the first reply takes the sacrificed piece on its square — and check whether the resulting play is checkmate.
- If the main line itself reaches mate, that settles it. If it stops just short, we still accept the position when mate is now unavoidable: it is mate in one for us, or every legal enemy reply still lets us mate on the next move.
- As a backstop, if no line is supplied we imagine the opponent simply grabbing the piece and ask whether we then have a mate in one or a short forced mate in two. Only then do we call it bombardinio.
Suppression Bombardinio outranks Destroying
- A king-side sacrifice often also looks like a Destroying sacrifice (smashing the pawn shield in front of the king).
- When both would fire, bombardinio is the stronger statement — it names the forced mate, not merely the broken shelter — so it suppresses Destroying and is reported alone.
Test positions (the examples that guard against regressions)