In soccer, hockey and baseball, the confirmed lineup drops at a predictable time before first whistle — an hour out in the Premier League, on the morning skate in the NHL — and it can swing a match materially, particularly the starting goaltender or pitcher. Until that moment, the market prices an average across plausible lineups. You pre-model each likely lineup's win probability so that when the sheet posts, you already know the new fair price and can act inside seconds.
Markets on Polymarket where starting-lineup & goalie-confirmation snap is the natural play:
