Cleveland Guardians vs. Philadelphia Phillies

Platform comparison

Active sub-markets

Market context

The Cleveland Guardians travel to Philadelphia on 23 May for an afternoon matchup against the Phillies, with first pitch at 4:05 PM ET. The current 38% implied probability for a Guardians victory reflects Philadelphia's standing as the favoured side. Across major prediction platforms, this same fixture shows notable variance in how the odds are presented: Polymarket displays the probability directly at 38%, whilst Kalshi and Betfair would express equivalent positions as decimal odds around 2.63 and 2.60 respectively. The fee structures differ meaningfully—Kalshi charges a flat 2% settlement fee on winning positions, whereas Betfair's commission scales with liquidity, and Polymarket applies a 2% fee at resolution. For traders comparing platforms on this specific market, liquidity depth and withdrawal timelines vary considerably, with Smarkets typically offering tighter spreads on major sports events but lower overall volume than Polymarket's baseball markets.

Historical context suggests the Guardians' 38% probability sits slightly below their expected win rate based on recent form. Cleveland finished 2023 with a 92-70 record and reached the World Series, whilst Philadelphia's 2024 campaign has positioned them as NL East contenders. Pitching matchups and bullpen availability often shift these probabilities by 3–5 percentage points in the final 48 hours before game time.

Traders should monitor roster updates through 22 May, particularly injury reports affecting starting pitchers or key relievers. Weather conditions at Citizens Bank Park—afternoon games in late May occasionally see temperature swings affecting ball carry—represent a secondary catalyst. The settlement window closes 30 May at 20:05 UTC, allowing five days for any postponement resolution.

Methodology

This page compares Cleveland Guardians vs. Philadelphia Phillies specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. Live odds come from the Polymarket order book; the other venues' contract details are maintained manually because their APIs aren't directly comparable. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

Where can I trade this market with the lowest fees?

On PolyGram, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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 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 fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

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.