Seattle Mariners vs. Pittsburgh Pirates

Platform comparison

Active sub-markets

Market context

The upcoming MLB game between the Seattle Mariners and Pittsburgh Pirates, scheduled for June 24 at 6:40PM ET, will determine whether the Mariners win or the Pirates secure victory. With a current crowd-implied probability of just 7% favouring the Mariners, the market heavily anticipates a Pirates win, though the possibility of a tie or cancellation remains open for a 50-50 resolution.

Historically, such low probabilities for a team with a 41-39 record often signal a critical injury or lineup disruption rather than pure form. The Mariners have recently placed key infielder Brendan Donovan on the 10-day injured list due to a strained left groin, while pitcher Logan Evans faces a 60-day absence for an arm issue[2][3]. These absences mirror past scenarios where a 7% win probability for a mid-table team correctly predicted a loss due to depleted depth, as seen when Donovan’s groin strain significantly weakened their offensive output in recent away games[1].

Traders must monitor the official starting lineups and any further injury updates before the 6:40PM ET start, as the absence of Donovan and Evans could shift the line further against the Mariners[2]. The Pirates, sitting at 39-40 with a solid home record of 20-20, are poised to capitalise on these weaknesses, but any delay or cancellation would reset the market to 50-50. Recent reports confirm Donovan’s groin injury as the primary catalyst, making his availability the single most important dependency for this outcome[2].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Seattle Mariners vs. Pittsburgh Pirates on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

On Champions League Prediction, 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'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 Champions League Prediction?

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

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Champions League Prediction triggers a quick verification flow that finishes in minutes.