Modell v21 Pre-Release

Five champion generations. v17 → v18 → v19 → v20 → v21 — every promotion had to win a paired SPRT arena gating first. The reigning champion v21_2d_brierbest sits at Elo 1358, measured against a handcrafted heuristic anchored at 1000.

New architecture. A 2D encoder (conv branch over 6×6 board planes plus a flat feature branch), and a value head that predicts a win probability (WDL) instead of a squashed point margin — measurably better calibrated. Win probabilities shown in the UI are Platt-corrected per champion.

Exact endgames. Round 5 is no longer played by the network but solved by expectiminimax, with chance nodes at the points where hidden information is revealed.

Under the hood. The search got its own RNG, so games are reproducible; four copied game loops became one; training labels no longer depend on machine load; and every runtime knob now lives in a registry with a guard test that fails the build if one goes undocumented.

Bundle. Ships the reigning champion (v16 shipped a long-outdated network) and the Elo history, so games against the AI are rated. Rules manual and readme are in English now, with proper attribution to Azul Duel.

Still German: the game UI. Still missing: difficulty presets — turning the simulations down does not make the AI a beginner, since its endgame stays exact.