How do I evaluate an endgame where I'm up a soldier but down the exchange?
These answers restate the rules implemented by our open-source engine, which follows the WXF laws and is regression-tested against the official 110-diagram repetition casebook. Where an answer refers to a specific position, that position lives on the linked reference page, where the build verifies it against the engine before publishing.
Direct answer
Generally, the side down the exchange is worse off, even with an extra soldier, since a chariot is normally worth considerably more than the gap between it and whatever lesser piece was traded for it, and one extra soldier rarely closes that gap on its own. But this is a guideline, not a fixed rule, and the activity of the remaining pieces can tip a specific position either way.
Why material alone does not settle it
The exchange, typically a chariot for a horse or cannon, is a real and usually significant material deficit, and a single soldier is the smallest unit of material on the board. On raw value the side down the exchange is worse, but xiangqi endgames are decided by more than a value table, and an active extra soldier that is close to promotion-equivalent advance, or well-placed defending pieces, can outweigh a small material gap.
What actually to weigh alongside the raw count
Whether the extra soldier is genuinely dangerous, close to the enemy palace with real threats, or just sitting passively, and whether the side down the exchange has an active, well-coordinated remaining piece or a genuinely weak one. See piece values for the baseline this comparison starts from before activity is factored in.
Related questions
Is this the kind of imbalance worth playing for a win with?
Often for the side with the exchange advantage, though a genuinely strong extra soldier can make it a fight rather than a clear edge.
Does this change much in a pure soldier-versus-soldier race?
Yes, considerably; see calculating a soldier race for when soldier activity becomes the deciding factor outright.
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