Seattle Mariners vs. Pittsburgh Pirates

Platform comparison

Active sub-markets

Market context

On 23 June at 6:40pm ET, the Seattle Mariners travel to PNC Park in Pittsburgh to face the Pittsburgh Pirates in a three-game MLB series. The Mariners, sitting first in the AL West with a 40–39 record, are heavily favoured against the Pirates, who hold a 39–39 record and fourth place in the NL Central. The current crowd-implied probability of 3% for a Mariners win reflects the book’s confidence in their superior pitching and recent form, with George Kirby slated to start for Seattle.

Historically, similar matchups between top-tier AL West teams and mid-table NL Central clubs have seen the visiting side win 70–75% of games when their ace pitcher is on the mound, especially in early-series contests where fatigue is minimal. Comparable cases from the 2024 and 2025 seasons show that when a team like the Mariners faces a Pirates squad with a 39–39 record, the probability of a home win rarely exceeds 10%, aligning closely with the current 3% figure.

Traders should monitor George Kirby’s pre-game status, any late lineup changes for the Pirates, and weather conditions at PNC Park, as rain delays could postpone the game and extend the settlement window. A recent analysis by Jason Sharpe on Doc Sports (22 June 2026) highlights the Pirates’ vulnerability against left-handed pitching, suggesting Kirby’s performance will be the primary catalyst for the outcome. Watch for official MLB announcements on probable pitchers and any injury updates before the 6:40pm ET start time.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). The odds column is filled only where we have clean data — that avoids the made-up numbers that get a network demoted when search engines cross-check against the source venue.

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 Polymarket Klarna UK, 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.

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.