Polymarket guides, free tools, and comparisons

Guides

• Is that Polymarket trader skilled or lucky?: What the 2026 studies found about how rare demonstrated skill is, why profit and win rate cannot answer the question, and the price-relative test that can.
• What is a good win rate on Polymarket?: The empirical answer from the graded wallet population: median win rates by evidence depth, what the entry prices already implied, and how many records survive a luck test.
• How accurate are Polymarket NFL and college football odds?: The 2025 season's game-winner markets in OVERROUND's record (283 NFL, 797 college), priced a day before they resolved: how often the favorite won at each price, with 95% intervals.
• How accurate are Polymarket election odds?: The 2024 general election's 94 race-winner markets in OVERROUND's record, priced at three fixed cutoffs, with how often the favorite won and 95% intervals. Plus every U.S. Senate and state governor race under Polymarket's midterms tag, with links.
• The most accurate Polymarket traders: Each category's top-graded forecaster, measured against the prices they actually paid rather than profit, refreshed as markets resolve.
• The Polymarket leaderboard: profit ranks and win rates: How the official profit leaderboard works, why the win rates behind it only make sense next to entry prices, and how the ten biggest all-time winners grade as a group.
• Copy trading: what the graded data shows: Before mirroring any wallet: what graded records say about P&L leaderboards, win rates, entry lag, and style risk.

Free tools

• Wallet checker: Paste any Polymarket wallet address and see whether its graded record beats its own entry prices or stays consistent with luck.
• Skill-or-luck calculator: Type a record (resolved events, wins, average entry price) and test whether it is distinguishable from luck. No wallet address, no signup, nothing stored.

Benchmarks

• How accurate is Polymarket? The 2026 Q3 calibration benchmark: Independent, horizon-controlled accuracy from a year of resolved markets: calibration curves, Brier scores, category splits, and why the public figures disagree.

Comparisons and reviews

• OVERROUND vs Arkham Prediction Market Elo: Both rank Polymarket traders by accuracy rather than profit; the four checkable differences, sourced from Arkham's own announcement.
• Arkham Elo: review and alternatives: What Arkham's rating measures, the limits its own announcement states, and the verified alternatives.
• Polyburg review: Polyburg's free alerts, $79 Pro tier and copy-trading membership, checked against its live pages, and the alternatives.

The primary sources behind every page

The numbers in these guides come from the same pipeline that serves the product. The scoring method is described on the methodology page, its out-of-time validation is published in full on the research page, the aggregate calibration data is on the statistics page, and every position the service has alerted is graded in public on the receipts ledger, losses included.