Choose your next move
e2-e4Interactive Curve
Difference Explorer
Interactive win, draw, and loss probability curves across rating differentials [-800, +800].
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c7-c5Reverse Solver
Goal Engine
Reverse Elo solver: find required scores, win distributions, and matches to reach your target rating.
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g1-f3Trajectory
What-If Timeline
Simulate multi-round tournament scenarios and prospective rating milestones before you play.
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d7-d6Quick Delta
Single-Game Studio
Instant single-match rating deltas, expected scores, and win/draw/loss probability distributions.
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d2-d4FIDE Rp
Performance Rating (Rp)
Compute official FIDE Table 8.1b lookup and iterative tournament performance ratings.
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c8-d7Local Cache
Calculation History
Review and recall your previous calculations and simulations saved in your browser.
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