Profit per round, last 30% of each episode. High bidder (top of each cell) · Low bidder (bottom).
✓ best / ✓ best is that bidder’s best response to the opponent’s choice — the better of LLM vs Hedge in that row or column. A strategy is dominant only if it is best against both of the opponent’s strategies.
SPA: no dominant strategy for either bidder, and no cell is a mutual best response (no cell has ✓ on both lines).
FPA: Hedge is dominant for both bidders (✓ best in every column for high, every row for low). Hedge/Hedge is the mutual best response.