Kenshy: Arena

Kenshy: Arena is a practice room for forecasters. It grades your probability estimates against contracts that have already resolved, then audits the book you have actually built. It is not a broker, it places no orders, and it is not affiliated with any exchange. DAILY CALIBRATION ROUNDS Every day brings a deck of eight resolved prediction questions — real historical wording, category, closing date and the price the market itself finished at. The outcome stays hidden until you commit. • Drag the probability dial, lock your forecast, and see the outcome instantly • Per-question Brier score, market close comparison and a plain-English delta verdict • Round scorecard with mean Brier, log loss, hit rate and a bias reading • Practice sets of 5, 10 or 20 questions by category, drawn from unseen questions • Live crowd tape showing how other devices forecast the same question CALIBRATION PROFILE • Ten-bucket calibration curve plotted against observed frequency • Brier trend over your last 10, 30 or all rounds • Per-category table showing where you read the world well and where you read it as a fan • Confidence-band breakdown for forecasts below 20, mid-range and above 80 • Blowup count for every forecast more than 30 points from the outcome PORTFOLIO DOCTOR Type your open positions by hand — ticker, category, theme tags, side, size, average price in cents and resolution date. Positions never leave your device. • Five diagnoses: category concentration, theme clustering, resolution-date bunching, directional tilt and price-band exposure • Each diagnosis carries a severity level, a plain sentence naming the hidden correlation, and the single number that would clear it • Risk score 0–100 with a letter grade and a ring that animates on recompute • Resolution calendar showing which days carry too much of the book • Capital at risk, maximum payout and break-even probability computed as you type • Cross-check against signals that call your holdings already priced in • Export positions, round history and the full Doctor report as files SIGNALS FEED • Headline-to-market cards: a story, a three-sentence summary, and the exact contracts it touches • Priced-in score from 0 to 100 with a rationale for why the move is or is not already in the quote • Vote "already priced in" or "room to move" and see the crowd split • Filter by category, tracked items, or priced-in band • Log a position straight from any contract card LEADERBOARD AND STREAKS • Weekly and all-time rankings by mean Brier against every device that played the same decks • Rounds re-scored server-side, so scores cannot be edited on the client • Seven-day streak strip and longest-streak tracking • Fill Window, a sixty-second timing drill, keeps a streak alive on a day with no time for a full round BUILT TO WORK OFFLINE • The last deck, taxonomy, forty signals, every round, position and scorecard live on the device • A round played offline is scored locally and uploaded when the network returns, keyed so a retry never double-counts • Cached content appears immediately; a thin strip states when it was last refreshed PRIVACY No account, no email, no password. Identity is a single anonymous device code. Positions are never uploaded. Educational tool. Not affiliated with, endorsed by, or connected to Kalshi. No trading, no orders, no money. Nothing here is financial advice.