What happened
One contract, two games, two answers.
Both venues named the game by date, time, and teams. When it was rescheduled into a September 25 doubleheader, that description pointed at two games. Kalshi settled on game 1, which the Orioles won. Polymarket US settled on game 2, which the Yankees won. Each matches a record on MLB.com. I found it because I was running a cross-venue arbitrage experiment that paired these contracts, and it took a loss on both pairs.
The point
Even a baseball game can be hard to resolve as an event contract.
A contract is not an event; it is a model of an event. When the schedule moved, one description fit two games, and the venues made different decisions about how to handle it.
Everything is in the repo: raw responses from both venues and MLB, the press release, the contract terms, the bot's trades, and a verify.py that checks the core claims against the saved sources. No API keys needed.
Repo | Cimarron Data