San Francisco Giants vs St. Louis Cardinals Prediction Market Odds, September 16, 2026
| Spread | Total | ML | Best ML | |
|---|---|---|---|---|
â–¶Giants | +1.5 58%59% | O 8.5 48%48% | 41%41% | 41% Kalshi |
â–¶Cardinals | -1.5 42%41% | U 8.5 52%52% | 60%59% | 60% Kalshi |
| Spread | Total | Moneyline | Best ML | |
|---|---|---|---|---|
â–¶San Francisco Giants | +1.5 | O 8.5 | 41% Kalshi | |
â–¶St. Louis Cardinals | -1.5 | U 8.5 | 60% Kalshi |
St. Louis is the moneyline favorite for the series finale against San Francisco at Busch Stadium, priced at 60 percent on Kalshi and 59 percent on Polymarket, an average of 59.5 percent. The two books sit one point apart on the favorite and one point apart on the Giants side (41 percent Kalshi, 42 percent Polymarket), so there is no cross-platform edge to take here as of the September 15 capture. The Cardinals are 75-76 and 37-39 at home; the Giants are 62-89 and 26-50 on the road, which is the gap the price is paying for.
St. Louis enters the finale at 75-76 and San Francisco at 62-89, and the moneyline is doing exactly what that record gap implies: the Cardinals are the 59.5 percent favorite (60 percent Kalshi, 59 percent Polymarket) and the Giants are 41.5 percent (41 percent Kalshi, 42 percent Polymarket). Both books total 101 across the two sides, so the vig on this game is about as thin as an MLB board gets. First pitch is 1:15 PM ET, a getaway-day matinee, and the board carries roughly $1,557 in volume across two platforms, which makes it one of the lighter MLB markets on the September 16 slate.
Giants vs Cardinals Market Context
The road record is the whole story of the price. San Francisco is 26-50 away from home, a .342 clip, against a Cardinals club that is 37-39 at Busch and actually better on the road at 38-37. A 59.5 percent home favorite implies St. Louis wins this roughly three times in five, which is a modest number for a home team facing a 62-89 opponent, and the reason is the pitching matchup. Matthew Liberatore, listed as the Cardinals probable starter as of September 15, is 5-14 with a 5.53 ERA. Anthony Molina, listed as the Giants probable as of September 15, is 3-1 with a 5.24 ERA in limited work. Two starters north of a 5.00 ERA is why the market is not pushing St. Louis further up, and it is why the run environment markets are priced the way they are.
Neither team is playing for anything structural. The Cardinals are a game under .500 with eleven to play and the Giants are 27 games under, so this is a finale between clubs with roster churn and short leashes on starters, which historically widens the tails on a game total rather than tightening the moneyline.
What the Spread and Total Say
The alternate lines on this board are quoted on Polymarket only, so read them as one venue's book rather than a cross-platform consensus. St. Louis at -1.5 prices at 40 percent and at -2.5 at 30 percent; San Francisco at -1.5 sits at 30 percent and at -2.5 at 22 percent. The gap between the Cardinals moneyline at 59.5 percent and the Cardinals run line at 40 percent says the market expects a close game rather than a comfortable one, roughly a one-in-three chance St. Louis wins by exactly one run.
On totals, over 7.5 is 55 percent, over 8.5 is 47 percent and over 9.5 is 36 percent, which centers the expected score right around 8.5 runs. The first five innings market agrees: over 4.5 through five is 49 percent, a coin flip, with over 5.5 down at 37 percent. There is also a first-inning run market trading at 48 percent on both Kalshi and Polymarket, one of the few rungs outside the moneyline where both books are quoted and they agree exactly.
On line movement, be precise about what the board actually captured. The two moneyline legs each carry a single snapshot, so there is no open-to-now move to report on this game yet. The one line with a real series is the Polymarket over 7.5, which held between 55 and 56 percent across four captures in the hour after midnight UTC on September 16. Every other rung on the board is uncaptured rather than flat, and the finale board is young enough that the movement story will be written on game morning.
When the Giants vs Cardinals Market Resolves
The moneyline resolves to the winner of the September 16, 2026 game at Busch Stadium, settled on Kalshi and Polymarket once the game is official and final. Run line and total contracts settle on the final score including extra innings, and the first-five-innings markets settle on the score after five completed innings.
Key Giants vs Cardinals Catalysts
Pitching matchup: Liberatore (5-14, 5.53 ERA) against Molina (3-1, 5.24 ERA), both listed as probables as of September 15, is a matchup that argues for runs rather than a pitchers duel.
The road split: San Francisco is 26-50 away from home, and that .342 road record is the single most load-bearing number behind a 59.5 percent home favorite.
Home field is not an edge here: the Cardinals are 37-39 at Busch and 38-37 on the road, so the venue is doing less work in this price than the records suggest.
One-book alternate lines: every spread and total rung is quoted on Polymarket only, so there is no second book to arbitrage against on the run line or the total.
Thin liquidity: roughly $1,557 across two platforms means a modest order can move this board, and a getaway-day matinee gets less late attention than a night game.
Lineup risk on a 1:15 PM ET finale: day games after night games in a lost season produce rest-day lineups, and that risk sits on the Giants side more heavily at 62-89.
Related MLB Markets
The first two games of this set are on the board at the series opener on September 14 and game two on September 15. For season-long context, the St. Louis Cardinals team hub and the San Francisco Giants team hub track every market on each club, and the full slate lives on the MLB league hub.
Resolution Criteria
Resolves to the team that wins the San Francisco Giants at St. Louis Cardinals game scheduled for 1:15 PM ET on September 16, 2026 at Busch Stadium. Each winning team contract pays $1 per share and the losing side resolves to $0. Run line contracts (-1.5 and -2.5) and total contracts (over/under 7.5, 8.5 and 9.5) settle on the final score including extra innings, and the first-five-innings markets settle on the score after five completed innings. Kalshi and Polymarket settle once the game is official and final on the scheduled date. If the game is postponed, suspended or shortened before it becomes an official game, each platform applies its own postponement and void rules, which generally push settlement to the completion date or cancel the contract.
Key Factors
- Probable starters: Matthew Liberatore (5-14, 5.53 ERA) for St. Louis against Anthony Molina (3-1, 5.24 ERA) for San Francisco, both listed as of September 15
- San Francisco is 26-50 on the road, the number doing the most work behind a 59.5 percent Cardinals price
- St. Louis is 37-39 at Busch Stadium and 38-37 away, so home field is adding less than the moneyline implies
- Kalshi and Polymarket are one point apart on both moneyline sides, leaving no cross-platform value spot
- Every spread and total rung is quoted on Polymarket only, so the run line and total carry no second book
- Board volume is roughly $1,557 across two platforms, thin enough that a modest order moves the price
What are the current Giants vs Cardinals odds?
As of the September 15, 2026 capture, St. Louis is the favorite at 59.5 percent (60 percent on Kalshi, 59 percent on Polymarket) and San Francisco is at 41.5 percent (41 percent on Kalshi, 42 percent on Polymarket). The live board above carries the current prices.
Where does this game trade?
The moneyline trades on both Kalshi and Polymarket, and this page compares the two side by side. The run line, the game total and the first-five-innings markets are quoted on Polymarket only on this board.
Who is favored and by what implied probability?
St. Louis is favored at an implied 59.5 percent, roughly a three-in-five chance of winning. That is a modest number for a home favorite because both listed probable starters carry an ERA above 5.00.
When does the Giants vs Cardinals market resolve?
First pitch is 1:15 PM ET on September 16, 2026 at Busch Stadium. Contracts settle on Kalshi and Polymarket once the game is official and final, usually within a few hours of the last out.
What are the spread and total?
St. Louis at -1.5 prices at 40 percent and San Francisco at -1.5 at 30 percent. On totals, over 7.5 is 55 percent, over 8.5 is 47 percent and over 9.5 is 36 percent, which centers the expected score near 8.5 runs.
Has the line moved?
Not measurably yet. The two moneyline legs each carry a single snapshot on this board, so there is no open-to-now move to report. The Polymarket over 7.5 held between 55 and 56 percent across four captures in the hour after midnight UTC on September 16.