{"uid":"cap_jymPAVFHJYJggYzaATqcX","slug":"kelly-fraction-calculator-b3273dbf","name":"Kelly Fraction Calculator","description":"Kelly fraction from win probability and net payoff odds b. Call when bankroll sizing for repeated bets with known edge (advisory). Returns full Kelly fraction clamped to [0,1] as deterministic JSON for $0.001 USDC via x402 on Base. First-party local math only—no RPC, live market feed, API keys, storage, or mediagen. Advisory only; the caller owns capital, risk, and production controls.","url":"https://api.delx.ai/api/v1/x402/kelly-fraction","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"b":{"type":"number","description":"Input field: b."},"win_prob":{"type":"number","description":"Input field: win prob."}}},"responseSchema":{"type":"json","example":{"b":1.2,"kelly":0.175,"schema":"delx/util-kelly-fraction/v1","win_prob":0.55}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_Lj2Tn4HylUvyuNwloLwgP","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes the full Kelly criterion fraction from win probability and net payoff odds for optimal bankroll sizing","exampleAgentPrompt":"What fraction of my bankroll should I bet according to the Kelly criterion if I have a 60% chance of winning and the net payoff odds are 1.5?","exampleUseCases":[{"title":"Sports betting bankroll sizing","prompt":"I'm placing repeated bets on a sports market where I estimate a 58% win probability and the bookmaker is offering net odds of 1.8. What does Kelly say my optimal bet fraction should be?"},{"title":"Trading edge position sizing","prompt":"I've backtested a strategy with a 55% win rate and average win/loss ratio of 2.0, meaning b is 2. Can you calculate the Kelly fraction so I know how much of my capital to deploy per trade?"},{"title":"Poker bankroll management","prompt":"In a poker spot I estimate I'm a 65% favorite and the effective net payoff if I win is 1.2 times my bet. What's the full Kelly fraction I should use for bankroll sizing?"}],"resultDescription":"A deterministic JSON response containing the full Kelly fraction clamped to the range [0, 1], representing the optimal proportion of the bankroll to wager given the supplied win probability and net payoff odds. No external data sources are consulted — the result is computed from local math only.","failureModes":["Missing required fields (win_prob or b not provided) returns a validation error","win_prob outside [0, 1] may return an error or produce a degenerate result","b <= 0 (zero or negative net payoff) produces undefined or clamped output","Negative Kelly fraction (negative expected value bets) clamped to 0","Floating point precision edge cases near boundary conditions"],"whenToPreferThis":"Use this endpoint when you need a fast, deterministic, local-math-only Kelly criterion computation with no API keys, RPC calls, or live market data required. Ideal for agents performing bankroll sizing in advisory mode for repeated bets or trades where win probability and net payoff odds are already known. Prefer this over a general-purpose calculator or LLM math when you need a structured JSON result, guaranteed clamping to [0,1], and micropayment-based access at $0.001 USDC per call.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T07:14:56.906Z","isFirstParty":false}