1. STRICT FORCED CHECKMATES (MATE-IN-2 TO MATE-IN-5)
The Gatekeeper rejects puzzles where the goal is merely to win an exchange or enter a slightly better endgame. Every test is an uncompromising execution: King hunts, queen sacrifices, back-rank clearances, smothered mates, and deflections.
Two puzzles are presented per calibration session. Your performance is averaged across both trials to eliminate lucky misclicks and measure genuine tactical acuity.
2. THE 90-SECOND DECAYING RATING CLOCK
In speed and rapid chess, finding the right move after five minutes is useless if your flag falls. The Gatekeeper ties tactical Elo directly to calculation velocity:
Solving within the first few seconds proves immediate tactical pattern recognition and locks in maximum Elo.
Using the entire 90 seconds still credits a successful solve, establishing a solid foundational baseline.
3. MULTI-SOLUTION FORCED MATE ENGINE
Traditional puzzle sites penalize players if they find an equally crushing or faster mating line that wasn't in the database author's single PGN file.
Eternal Gambit evaluates moves dynamically. Any legal continuation that forces checkmate within the required ply budget is approved, and the engine automatically generates genuine legal defensive replies.
FREQUENTLY ASKED QUESTIONS
What makes the Gatekeeper different from standard daily chess puzzles?
Standard chess puzzles often test vague positional advantages (+1.5 advantage, win a pawn). The Gatekeeper tests exclusively forced checkmates (mate-in-2 through mate-in-5). Every single puzzle has an absolute, non-negotiable checkmate sequence at the end of the line.
How does the decaying rating clock work?
You have a 90-second solve window. Solving immediately yields the maximum placement rating (up to 2400 Elo). As the clock ticks down, your earned Elo decays smoothly toward a baseline of 1400. This rewards tactical instinct and rapid calculation over slow trial-and-error.
Does the solver recognize alternative checkmating moves?
Yes. The Gatekeeper uses a multi-solution minimax engine verification. If you discover a sound, alternative checkmate that forces mate within the required ply budget, the system accepts it and computes legal defensive replies dynamically.
TEST YOUR TACTICAL SPEED TODAY
The clock starts the moment you view the board. Authenticate your tactical sight and claim your starting rating.
LAUNCH TODAY'S GATEKEEPER →