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the library · reviewed 2026-08-24

Tudor – Ratkovic

RUDAR 27 GM 2025 · 2025.12.11 · Elo 2430/2445 · defensive · ★★★
The daily position for Sunday 23 August 2026. It is still open to solve — the grader reads your whole line, sidelines and evaluation included, before anything here is shown. Cover the solution and solve it first →
. . q . . . k .
p . . . . p . .
. . . p . P p Q
. p . P . R . P
. . . . . . . .
. . . . . . K .
P . r . . . . .
. . B . . . . .
Black to move. the model predicts 35% at this level.

The solution

34…♖︎c3+! (not 34…♕︎c3+? 35.♗︎e3 ♕︎e1+ 36.♗︎f2 ♕︎c3+ 37.♔︎g2 +−) 35.♔︎h4 (if 35.♖︎f3 then 35…♖︎xf3+ 36.♔︎xf3 ♕︎h3+ =) 35…♖︎h3+ 36.♔︎xh3 ♕︎xf5+ 37.♔︎g3 (37.♔︎h2 is as good: 37…♕︎f2+ 38.♔︎h3 ♕︎f3+ =) 37…♕︎e5+ (not 37…♕︎xf6? 38.♕︎f4 ♕︎a1 39.hxg6 fxg6 40.♗︎e3 +−) 38.♕︎f4 ♕︎e1+ ⩲

“hard to find”, “the natural move” and the rest describe how often this move is played by Maia-2, weighted across the 1500/1900/2000 audience the difficulty model is fitted on — a model of human play, not a count of anyone who solved this position.

Members can take this away as a PGN — the diagram, the verified line and their own analysis in one file, for a database, Anki or Chessable.

What happened at the board

Ratkovic played ♕︎c3+ instead · 1-0

in the game 34…♕︎c3+ 35.♗︎e3 ♕︎e1+ 36.♗︎f21-0full game ↗
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