Tigers vs Mariners Prediction Market Odds, August 5, 2026
| Spread | Total | ML | Best ML | |
|---|---|---|---|---|
▶Tigers | — | O 1 47%45% | 42%39% | 42% Kalshi |
▶Mariners | — | U 1 53%55% | 60%62% | 62% Polymarket |
| Spread | Total | Moneyline | Best ML | |
|---|---|---|---|---|
▶Detroit Tigers | — | O 1 | 42% Kalshi | |
▶Seattle Mariners | — | U 1 | 62% Polymarket |
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Seattle is the 55.5c home favorite (57c Kalshi, 54c Polymarket) over Detroit at 46c, and the market moved there inside 24 hours: the Tigers opened as the 53c side on Kalshi and have been sold 8c below that open. The price sits on top of a starter mismatch pointing the other way, with Troy Melton (6-1, 1.75 ERA) on the mound for Detroit against Bryan Woo (7-8, 4.56 ERA) for Seattle. Both clubs enter under .500, the Mariners at 55-58 and the Tigers at 54-58, for a 9:40 PM ET first pitch at T-Mobile Park.
The Tigers vs Mariners market prices Seattle at 55.5c and Detroit at 46c for the middle game of a three-game set at T-Mobile Park on Wednesday, August 5, 2026. That is a modest home edge, and it is being paid even though Detroit sends the better arm and holds the season series 2-1 through three meetings. The board carries roughly $1.9K in cross-platform volume across Kalshi and Polymarket, with a moneyline and a first-inning run market posted and no run line or total offered.
Tigers vs Mariners Records, Form, and Standings Stakes
Seattle is 55-58 overall and 32-24 at T-Mobile Park, sitting 2.5 games back of Houston (58-56) in the AL West and tied with Texas (55-58). The Mariners lost twice at Los Angeles to open the week, then took two of three from Minnesota, including a 7-6 win on August 2, 2026. Detroit is 54-58 with a 24-31 road record and is 5.5 back of Chicago (59-52) in the AL Central, but arrives on a three-game win streak after sweeping the Athletics by scores of 13-1, 8-6, and 11-0.
The home and road splits are the cleanest defense of the Seattle price. The Mariners are eight games over .500 at home; the Tigers are seven under on the road. That 15-game swing in venue-adjusted form is worth more to a pricing model than the four-game gap in overall record, which is one game in Detroit's favor. Both teams are priced as fringe contenders in their season markets: Seattle trades at 43c to reach the postseason and 36.5c (35c Kalshi, 38c Polymarket) in the AL West division market behind Houston at 45c, while Detroit's playoff market is down to 19c.
Tigers vs Mariners Pitching Matchup
Troy Melton (6-1, 1.75 ERA) starts for Detroit, working on 67 innings across 11 starts since he joined the rotation. Bryan Woo (7-8, 4.56 ERA) starts for Seattle. That is a 2.81-run ERA gap in Detroit's favor, and the market still has the Tigers as the 46c side, which is the single most interesting thing on this board. ESPN's matchup predictor sits on the opposite side of the price, projecting Detroit at 52.5% and Seattle at 47.5%.
The lineup edge partly explains the disconnect. Dillon Dingler carries Detroit's offense with 23 home runs and 72 RBI, and Kevin McGonigle hits .287, but the Tigers are without Kerry Carpenter (foot) and Matt Vierling (groin) on the 10-day injured list. Seattle counters with Randy Arozarena at .282, Dominic Canzone at 18 home runs, and Cole Young at 51 RBI, while missing J.P. Crawford (wrist) and Brendan Donovan (groin) from the lineup and Matt Brash (lat) from the bullpen. Neither club is at full strength, so the pitching line is doing most of the work in any model, and the market is discounting it.
Tigers vs Mariners Line Movement and Cross-Platform Pricing
Detroit opened at 53c on Kalshi on August 3, 2026 and traded up to 56c through that morning. From there the move reversed: 53c by late afternoon, 47c overnight, and 45c on the latest read. That is an 11c round trip off the high and 8c below the open. Seattle mirrored it exactly, opening at 51c, bottoming at 48c, and printing 57c on the last snapshot. Volume backed the move rather than a thin drift, with Kalshi's 24-hour moneyline volume expanding from roughly $267 to roughly $1.1K over the same window.
The two books do not agree on the size of the edge. Seattle is 57c on Kalshi and 54c on Polymarket, a 3c gap, so the cheaper Mariners ticket is on Polymarket. Detroit is 45c on Kalshi against 47c on Polymarket, so the cheaper Tigers ticket is on Kalshi. Kalshi's two sides sum to 102c and Polymarket's to 101c, which is a tight two-sided book for a mid-week game of this size. The wider disagreement is on the first-inning run market, where Kalshi prices a run in the first at 55c and Polymarket at 47c, an 8c spread on a contract carrying about $17 of Kalshi volume. At that size the gap reads as a liquidity artifact more than a genuine difference of opinion, and the moneyline is the only line on this board with enough two-sided flow to trust.
When the Tigers vs Mariners Market Resolves
The moneyline resolves to the team that wins the game at T-Mobile Park on Wednesday, August 5, 2026, first pitch scheduled for 9:40 PM ET. Each winning contract pays $1 per share and the losing side settles at zero, with both Kalshi and Polymarket settling on the official MLB result rather than a media call. A game shortened by weather still settles if it is official under MLB rules, with the leading team at the point of stoppage recorded as the winner. A postponement moves settlement to the completed makeup game under each platform's published rescheduling rule, and a game not completed inside that window voids. The companion first-inning market resolves YES if either team scores in the top or bottom of the first inning.
Key Tigers vs Mariners Factors
- Starter mismatch against the price: Melton (1.75 ERA) versus Woo (4.56 ERA) is a 2.81-run gap in Detroit's favor, and Detroit is still the 46c side.
- Venue split: Seattle is 32-24 at T-Mobile Park, Detroit is 24-31 on the road, the strongest single argument for the home price.
- Overnight repricing: Detroit went 56c to 45c on Kalshi with 24-hour volume expanding from roughly $267 to roughly $1.1K, so the move carried size.
- Cross-platform value spot: the Mariners are 3c cheaper on Polymarket at 54c, the Tigers are 2c cheaper on Kalshi at 45c.
- Model disagreement: ESPN's matchup predictor has Detroit at 52.5%, roughly 6.5 points above the Tigers' 46c market price.
- Series and standings stakes: Detroit leads the season series 2-1, Seattle is 2.5 back in the AL West at 43c to make the playoffs, Detroit is 5.5 back in the AL Central at 19c.
Related Tigers vs Mariners Markets
Both clubs have live season-long books alongside this game. The Seattle Mariners team hub tracks every Mariners contract, including the 43c postseason market and the AL West race behind Houston. The Detroit Tigers team hub covers the Tigers' side, where the 19c playoff price reflects a 5.5-game deficit with roughly 50 games left. For the rest of the day's slate and the full league board, the MLB prediction markets hub lists every game and futures market currently trading on Kalshi and Polymarket.
Resolution Criteria
The moneyline resolves to the team that wins the Detroit Tigers at Seattle Mariners game at T-Mobile Park on Wednesday, August 5, 2026, with a scheduled first pitch of 9:40 PM ET. Winning contracts pay $1 per share and losing contracts settle at zero. Both Kalshi and Polymarket settle on the official MLB result, so a weather-shortened game that is official under MLB rules settles to the team leading at the point of stoppage. If the game is postponed, settlement follows each platform's published rescheduling rule and moves to the completed makeup game; a contest not completed within that window voids and refunds. The companion first-inning contract resolves YES if either club scores at least one run in the top or bottom of the first inning, and NO if the inning is scoreless.
Key Factors
- Starter mismatch: Troy Melton (6-1, 1.75 ERA) for Detroit against Bryan Woo (7-8, 4.56 ERA) for Seattle, a 2.81-run ERA gap the market is discounting
- Venue split: Seattle 32-24 at T-Mobile Park versus Detroit 24-31 on the road, the strongest support for the 55.5c home price
- Overnight repricing: Detroit fell from 56c to 45c on Kalshi with 24-hour volume expanding from roughly $267 to roughly $1.1K
- Cross-platform value: Mariners 3c cheaper on Polymarket (54c versus 57c), Tigers 2c cheaper on Kalshi (45c versus 47c)
- Model disagreement: ESPN's matchup predictor projects Detroit at 52.5% against a 46c market price
- Standings stakes: Seattle 2.5 back in the AL West at 43c to make the playoffs, Detroit 5.5 back in the AL Central at 19c
What are the current Tigers vs Mariners odds?
On the board ahead of the August 5, 2026 first pitch, Seattle is the 55.5c favorite (57c on Kalshi, 54c on Polymarket) and Detroit is 46c (45c Kalshi, 47c Polymarket). That implies roughly a 56% win probability for the Mariners.
Who is favored in Tigers vs Mariners on August 5, 2026?
Seattle is favored at 55.5c despite a 55-58 record, one game worse in the standings than Detroit's 54-58. The home edge is the driver: the Mariners are 32-24 at T-Mobile Park while the Tigers are 24-31 on the road.
Who are the probable starting pitchers?
Detroit starts Troy Melton, who is 6-1 with a 1.75 ERA over 67 innings and 11 starts. Seattle starts Bryan Woo, who is 7-8 with a 4.56 ERA. The 2.81-run ERA gap favors Detroit even though Detroit is the 46c underdog.
How did the Tigers vs Mariners line move?
Detroit opened at 53c on Kalshi on August 3, 2026, traded as high as 56c, then reversed to 45c by the latest read. Seattle moved the other way from 51c to 57c, with Kalshi's 24-hour moneyline volume expanding from roughly $267 to roughly $1.1K.
Where does the Tigers vs Mariners market trade and when does it resolve?
The game trades on both Kalshi and Polymarket, with roughly $1.9K in combined volume. It resolves on the official MLB result after the August 5, 2026 game at T-Mobile Park, scheduled for 9:40 PM ET.
What should I watch before first pitch on August 5, 2026?
Watch the lineup card for J.P. Crawford (wrist) and Brendan Donovan (groin) in Seattle and Kerry Carpenter (foot) in Detroit, and watch whether the Tigers stabilize above 45c on Kalshi. A move back through 48c would signal the overnight sell-off is being faded.