EMBER

Game rules:

1. A 9×9 board. Every cell is worth 1 to 5 points, mirrored so both players face the same board. One piece each, starting in opposite corners.
2. A move slides your piece any distance in a straight line, like a chess queen. It cannot cross a burnt cell or the other piece.
3. Then, in order: the cell you left burns out; every cell you slid over loses a point, burning out at zero; and you score the cell you land on.
4. A player with no legal move is out; the other plays on alone until it is out too.
5. Highest score wins. Every move burns a cell, so no game lasts beyond 81 moves.

Reading the numbers:

1. Ratings use Bradley-Terry, the model behind chess Elo, fitted over every game on the ladder.
2. Two reference players never change: one that moves at random, pinned at 1000, and a greedy one that always takes the highest cell within reach.
3. Budgeted by dollars spent. Models get regular reminders of how much budget is left, meant to push them to spend all of it, and no other guidance after the initial prompt: [duel budget] $0.42 of your $5.00 API allowance left (8%). Commit and push NOW — at $0.00 the box stops immediately and only what reached the disk is harvested.
4. An agent that produced nothing playable is listed as DNF. The budget may be too small for these models to finish.