Twins vs Mariners Prediction Market Odds, July 31, 2026
| Spread | Total | ML | Best ML | |
|---|---|---|---|---|
â–¶Twins | +1.5 56%75% | O 8.5 44%44% | 38%38% | 38% Kalshi |
â–¶Mariners | -1.5 44%25% | U 8.5 56%56% | 63%63% | 63% Kalshi |
| Spread | Total | Moneyline | Best ML | |
|---|---|---|---|---|
â–¶Minnesota Twins | +1.5 | O 8.5 | 38% Kalshi | |
â–¶Seattle Mariners | -1.5 | U 8.5 | 63% Kalshi |
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Seattle is the 63.5c moneyline favorite (63c Kalshi, 64c Polymarket) over Minnesota at 37.5c, the widest single-game gap on the July 31, 2026 MLB slate, and the standings do not explain it. The Twins are 55-55 and 4-1 across their last five games; the Mariners are 53-56 and 2-3. The board is pricing the starting pitchers, Bryce Miller (4-5, 2.75 ERA, 0.92 WHIP) against Zebby Matthews (4-8, 5.21 ERA, 1.32 WHIP), on top of a 30-23 Seattle home record at T-Mobile Park.
Minnesota opens a weekend series at T-Mobile Park on July 31, 2026 with the better record and the worse price. The Twins are 55-55 and third in the AL Central, three games back of Chicago. The Mariners are 53-56 and third in the AL West, two games back of Texas. The market still makes Seattle a 63.5c favorite, the biggest single-game edge on the slate, and effectively all of that gap traces to who is on the mound.
Twins vs Mariners Market Context
Bryce Miller carries the price. The Seattle right-hander is 4-5 with a 2.75 ERA over 11 starts and 68.2 innings, with 71 strikeouts against a 0.92 WHIP. Zebby Matthews has thrown more innings (76.0 across 13 starts) for a materially worse return: 4-8, a 5.21 ERA, 59 strikeouts and a 1.32 WHIP. The 2.46-run ERA gap is the single largest input into the 63.5c line, and the 0.40 WHIP gap says the same thing about traffic on the bases.
Form cuts the other way. Minnesota is 4-1 over its last five, taking two of three from Kansas City including a 4-3 win on July 30, after a two-game sweep of the Athletics. Seattle is 2-3, dropping two of three at Texas and then losing 4-2 at the Dodgers on July 30. Venue is the offset: the Mariners are 30-23 at T-Mobile Park and 23-33 away from it, while the Twins are 25-28 on the road. Seattle leads the season series 2-1 with six games scheduled.
Both clubs are short-handed. Minnesota is without Byron Buxton (10-day injured list), leaving Kody Clemens (19 home runs) and Josh Bell (63 RBI) to carry the run production, with Luke Keaschall leading the regulars at .256. Seattle is without Brendan Donovan (10-day injured list) and reliever Matt Brash (15-day injured list). Randy Arozarena leads the Mariners at .278 and Dominic Canzone has 18 home runs with 49 RBI.
Twins vs Mariners Spread, Total, and First Five Read
The run line states the market's conviction more precisely than the moneyline does. Seattle at -1.5 trades at 44c (44c on both Kalshi and Polymarket), which implies roughly a 69% chance that a Seattle win is a multi-run win. Minnesota at -1.5 sits at 26.5c (27c Kalshi, 26c Polymarket). Stretch to -2.5 and Seattle is 33.5c against Minnesota's 18.5c, a 15-point gap that widens as the margin requirement grows.
The total is priced at 8. Over 7.5 runs is 53.5c (53c Kalshi, 54c Polymarket) and Over 8.5 is 46c on both platforms, which brackets the number cleanly. Team totals agree with that read: Seattle over 3.5 runs at 62c and over 4.5 at 48c implies about 4.4 runs, Minnesota over 3.5 at 47c and over 4.5 at 34c implies about 3.4, and the 7.8 sum lands within a fifth of a run of the game total.
The first-five-innings board is the cleanest expression of the pitcher gap, because it isolates the starters from the bullpens. Polymarket has Seattle leading after five at 53c, Minnesota at 32c, and a tie at 15c. Seattle -1.5 through five trades at 40.5c against Minnesota's 24c, and Over 4.5 runs in the first five is a coin flip at 51c. A run in the opening inning is priced at 49c on both platforms.
Twins vs Mariners Line Movement and Cross-Platform Pricing
The moneyline has not moved. Kalshi has held Seattle at 63c through every intraday snapshot in the current session, and Polymarket has printed Minnesota at 37c on all eight of its marks, which pins Seattle at 64c the whole way. There is no late repricing to chase here: the number opened where it sits, and the flat tape is itself information about how settled this matchup is.
Across platforms the two books are one cent apart on each side, so there is no divergence trade, only a best-execution question. A Seattle buyer pays 63c on Kalshi against 64c on Polymarket. A Minnesota buyer pays 37c on Polymarket against 38c on Kalshi. The board carries $5.7K in combined volume across the two platforms, thin enough that a single sized order moves the print, which is the usual condition on a same-day regular-season game.
The real disagreement is with the models rather than between the books. The ESPN matchup predictor gives Seattle 56.9%, which sits 6.6 points below the 63.5c market price. That is the whole case for the underdog: the projection systems weight Minnesota's .500 record and 4-1 run of form more heavily than the market does, and the market weights the 2.46-run starting-pitcher ERA gap more heavily than the models do. Minnesota at 37.5c is the value side only if you take the projection over the arm.
When the Twins vs Mariners Market Resolves
The moneyline resolves to the team that wins the game at T-Mobile Park on the night of July 31, 2026, with first pitch scheduled for 10:10 PM ET. Extra innings count and there is no draw outcome, so one side settles at $1 and the other at $0. The run line settles on the final margin and the game total on combined runs in the official final score, both typically within minutes of the last out.
Key Twins vs Mariners Catalysts
Starting pitching: Bryce Miller (2.75 ERA, 0.92 WHIP, 71 strikeouts in 68.2 innings) against Zebby Matthews (5.21 ERA, 1.32 WHIP) is the entire basis for the 63.5c price.
Home and road splits: Seattle is 30-23 at T-Mobile Park and 23-33 on the road, while Minnesota is 25-28 away from home.
Recent form the market ignored: Minnesota is 4-1 over its last five and Seattle is 2-3, and the line still favors the home side by 26 points of implied probability.
Availability: Byron Buxton is on the 10-day injured list for Minnesota; Brendan Donovan and Matt Brash are out for Seattle.
Model versus market: the ESPN matchup predictor has Seattle at 56.9%, 6.6 points under the traded price, the only meaningful disagreement on the board.
Flat tape: the moneyline has held at 63c on Kalshi and 64c on Polymarket through every snapshot, so any pre-game move would be new information rather than drift.
Related Twins vs Mariners and MLB Markets
Seattle's night game feeds directly into the AL West division market, where the Mariners sit two games back of Texas with Houston in between, and Minnesota's result carries into the AL Central race with the Twins three games back of Chicago. The full cross-platform board for every game on the schedule is on the MLB hub, and the rest of the day's slate with live Kalshi and Polymarket prices is on today's MLB games.
Resolution Criteria
The moneyline resolves to the team that wins the game at T-Mobile Park in Seattle on July 31, 2026, first pitch scheduled for 10:10 PM ET. Each team contract pays $1 per share if that team wins and $0 if it loses. Extra innings count toward the result and there is no draw or push outcome on the moneyline. The run line settles on the final margin, so Seattle at -1.5 pays only if the Mariners win by two runs or more, and the game total settles on the combined runs scored by both teams in the official final score. First-five-innings contracts settle on the score after the completion of the fifth inning. If the game is suspended, shortened, or called before it becomes an official game, Kalshi and Polymarket each apply their own game-completion and void rules, and a postponement to a later date is handled under each platform's published terms rather than settled on the scheduled date.
Key Factors
- Bryce Miller (2.75 ERA, 0.92 WHIP, 71 strikeouts in 68.2 innings) vs Zebby Matthews (5.21 ERA, 1.32 WHIP) is the basis for the 63.5c price
- Seattle is 30-23 at T-Mobile Park and 23-33 on the road; Minnesota is 25-28 away from home
- Minnesota is 4-1 over its last five and Seattle is 2-3, and the line still favors the home side
- Byron Buxton (10-day injured list) is out for Minnesota; Brendan Donovan and Matt Brash are out for Seattle
- The ESPN matchup predictor has Seattle at 56.9%, 6.6 points under the 63.5c traded price
- The moneyline has held flat at 63c on Kalshi and 64c on Polymarket through every intraday snapshot
What are the current Twins vs Mariners odds?
As of July 31, 2026, Seattle is the 63.5c moneyline favorite (63c on Kalshi, 64c on Polymarket) and Minnesota trades at 37.5c (38c Kalshi, 37c Polymarket). That prices the Mariners at roughly a 63% chance to win.
Who is favored in Twins vs Mariners on July 31, 2026?
Seattle, at an implied 63.5%. The market is pricing the starting pitching gap between Bryce Miller (2.75 ERA) and Zebby Matthews (5.21 ERA) rather than the records, since Minnesota is 55-55 and Seattle is 53-56.
Where can I trade the Twins vs Mariners market?
Both Kalshi and Polymarket list the game. Kalshi carries the deeper typed board covering moneyline, run line, game and team totals and first five innings, and the two platforms are within one cent of each other on both moneyline sides as of July 31, 2026.
What is the Twins vs Mariners run line and total?
Seattle at -1.5 trades at 44c on both platforms and Minnesota at -1.5 at 26.5c. The total is set at 8, with Over 7.5 runs at 53.5c and Over 8.5 runs at 46c on July 31, 2026.
When does the Twins vs Mariners market resolve?
It resolves when the game goes final at T-Mobile Park on the night of July 31, 2026, with first pitch scheduled for 10:10 PM ET. Contracts settle on both platforms shortly after the final out.
What should I watch before Twins vs Mariners resolves?
Whether the moneyline holds at 63c into first pitch, since it has not moved through a single intraday snapshot, and whether the ESPN model's 56.9% read on Seattle pulls the number back toward Minnesota at 37.5c.