{"uid":"cap_IpjgXMl4ITrR0xs5iAMnn","slug":"elo-rating-calculator-ee91c6e8","name":"Elo Rating Calculator","description":"Elo rating update after a game: win probability for each side, new ratings and the points exchanged.","url":"https://sports-calc.x402tookit.com/elo-rating?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["ratingA","ratingB","result"],"properties":{"k":{"type":"number","description":"K-factor, default 32"},"kB":{"type":"number","description":"K-factor for B if different"},"result":{"type":"string","description":"Result for A: win, draw, loss (or 1, 0.5, 0)"},"ratingA":{"type":"number","description":"Player A rating"},"ratingB":{"type":"number","description":"Player B rating"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"kA":{"type":["null","number"]},"kB":{"type":["null","number"]},"asOf":{"type":["null","string"]},"scoreA":{"type":["null","number"]},"source":{"type":["null","string"]},"changeA":{"type":["null","number"]},"changeB":{"type":["null","number"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"summary":{"type":["null","string"]},"verdict":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"expectedA":{"type":["null","number"]},"expectedB":{"type":["null","number"]},"disclaimer":{"type":["null","string"]},"newRatingA":{"type":["null","number"]},"newRatingB":{"type":["null","number"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"ratingDifference":{"type":["null","number"]}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","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":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_e2cglxoqmLOLrWbpV9KaU","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes win probabilities and updated Elo ratings for both players after a game result, including points exchanged.","exampleAgentPrompt":"Player A has an Elo rating of 1600 and player B has a rating of 1450 — player A just won the match. What are their new Elo ratings and how many points were exchanged, using the default K-factor of 32?","exampleUseCases":[{"title":"Chess match rating update","prompt":"I just beat an opponent rated 1800 in chess — my current rating is 1720. Using a K-factor of 32, what will my new Elo rating be and how many points do I gain?"},{"title":"Underdog win probability check","prompt":"What are the win probabilities for a player rated 1200 against a player rated 1550 before their game? I want to see the expected scores for both sides."},{"title":"Custom K-factor tournament update","prompt":"In our club tournament, player A rated 2100 lost to player B rated 1950. We use K=20 for player A and K=24 for player B — what are the new ratings for both players?"}],"resultDescription":"Returns win probability (expected score) for each player, the new updated Elo rating for each player, the rating points gained or lost by each, the K-factors used, and the original rating difference. May also include a summary verdict, source attribution, and disclaimer fields.","failureModes":["Missing required query params (ratingA, ratingB, or result) returns an error","Invalid result value (not 'win', 'draw', 'loss', '1', '0.5', or '0') causes a validation error","Non-numeric rating values cause a parsing error","Extremely large or negative rating values may produce unexpected results","Service degraded flag may be set if partial computation occurred"],"whenToPreferThis":"Use this endpoint when you need a standards-compliant Elo rating update calculation — including win probabilities, points exchanged, and support for asymmetric K-factors — without setting up your own formula. Ideal for chess, table tennis, esports leaderboards, or any head-to-head rated competition. Prefer this over general math endpoints when you specifically need Elo semantics (expected score formula, K-factor scaling, draw handling).","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-21T07:19:27.292Z","isFirstParty":false,"canonicalSlug":"elo-rating-calculator-ee91c6e8"}