Tampa Bay Rays vs. New York Yankees

Platform comparison

Active sub-markets

Market context

The Tampa Bay Rays travel to face the New York Yankees on 23 May at 1:35 PM ET in a regular-season matchup. The 45% implied probability for a Rays victory reflects modest underdog positioning, consistent with the Yankees' stronger recent record and home-field advantage. Across Polymarket, Kalshi, and Betfair, this same fixture shows fractional variance: Polymarket displays the probability directly at 45%, whilst Betfair's decimal odds (around 2.20 for Rays) and Kalshi's binary structure produce equivalent but differently-presented odds. Fee structures diverge meaningfully—Polymarket charges 2% on winnings, Kalshi typically 1.5% on certain sports markets, and Betfair's commission scales from 2% to 5% depending on volume. KYC requirements are tighter on Kalshi for US residents, whilst Polymarket and Smarkets serve broader jurisdictions with lighter verification.

Historical context matters here: the Rays have won 48% of their matchups against the Yankees over the past three seasons, though the Yankees hold a marginal edge in head-to-head records since 2022. The 45% probability sits slightly below that historical rate, suggesting the market is pricing in current-season form rather than long-term splits. Traders should monitor pitcher announcements—typically confirmed 24 hours before game time—as starting rotation quality has historically shifted these markets by 3–5 percentage points. Weather conditions at Yankee Stadium and any late roster changes due to injury will also influence movement. Recent form data from MLB.com and ESPN should be cross-referenced against each platform's closing odds to identify arbitrage opportunities before the settlement window closes on 30 May.

Methodology

We read Tampa Bay Rays vs. New York Yankees from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live quote comes directly from the Polygon order book; the other three are listed with their platform attributes — fees, KYC, settlement currency, payment options — because a 1:1 contract comparison without API access would be guesswork.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). PolyGram routes every trade directly into Polymarket's on-chain settlement, which is why payouts land fastest.

FAQ

Is this market available outside the US?

PolyGram is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does it cost to trade on PolyGram?

Zero. PolyGram routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.