Evidence library
Solitaire research and data
Explore PlaySolitaire’s measured win rates, hardest-games analysis and public gameplay methodology, with versioned data and clearly stated limits.
Measured report
Solitaire Win Rates
Explore versioned player results, sample sizes, uncertainty and the separate solver evidence.
Explore the win-rate reportEvidence analysis
Hardest Solitaire Games
See how measured results and solver evidence inform an editorial comparison of Solitaire difficulty.
Read the difficulty analysisPublic methodology
Solitaire Win-Rate Methodology
Review the definitions, cohort rules, limitations, corrections and reproducible calculations behind the report.
Review the methodologyProbability and interpreting results
Solitaire Opening Aces: Exact Probabilities Explained
Calculate the chance of zero, one or several Aces among Klondike’s seven opening face-up cards, with assumptions and reproducible Python.
Solitaire Losing Streaks: Probability Without the Myths
Use a transparent probability model to compare fixed losing streaks with runs across a session, without treating a toy win rate as player data.
Random vs Winnable Solitaire Deals: What Changes?
Separate random selection, solver certification and player completion using a ten-deal example, clear assumptions and reproducible arithmetic.
Draw 1 vs Draw 3 Win Rates: Why the Comparison Is Tricky
Recalculate the frozen August 2026 Draw 1 and Draw 3 results, then use a labeled example to see how player selection can reverse an overall comparison.
For history, scoring and game comparisons, explore the Solitaire blog.