Orioles vs Astros Prediction Market Odds, July 18, 2026
| Spread | Total | ML | Best ML | |
|---|---|---|---|---|
â–¶Orioles | -1.5 33%38% | O 8.5 52%52% | 51%50% | 51% Kalshi |
â–¶Astros | +1.5 67%62% | U 8.5 48%48% | 50%51% | 51% Polymarket |
| Spread | Total | Moneyline | Best ML | |
|---|---|---|---|---|
â–¶Baltimore Orioles | -1.5 | O 8.5 | 51% Kalshi | |
â–¶Houston Astros | +1.5 | U 8.5 | 51% Polymarket |
The Orioles vs Astros market is a coin flip for the second straight day, with no favorite priced for Saturday's rematch in Houston. Kalshi holds Houston at 51c and Baltimore at 50c while Polymarket flips it to Baltimore 51c and Houston 50c, so each book summing to 101c is vig rather than a lean. Baltimore (47-51) took Friday's series opener 3-2 at Daikin Park to pull within a game of Houston (47-52), and the pitching matchup is just as even: Trevor Rogers (6-7, 4.48 ERA) starts for Baltimore against Spencer Arrighetti (7-5, 4.50 ERA) on July 18, 2026. The live board above carries the current moneyline, run line, and total.
For the second consecutive day, prediction markets refuse to pick a side in this series. Saturday's Orioles vs Astros game at Daikin Park trades at 50c and 51c in every direction: Kalshi has Houston 51c over Baltimore 50c, Polymarket has Baltimore 51c over Houston 50c, and each book summing to 101c is the vig, not a read. Roughly $15K in combined volume has traded on the game, with the Kalshi tape slightly heavier on the Houston side, $3.9K against $2.7K. Baltimore won the series opener 3-2 on Friday and the board did not move; the market re-priced the rematch as the same coin flip.
Orioles vs Astros Odds and Matchup Context
The records justify the indecision. Baltimore is 47-51 overall and 19-26 on the road; Houston is 47-52 and barely better at home at 23-25. Friday's 3-2 Orioles win pulled Baltimore within a game of Houston, and the offenses carry a clear headliner apiece: Yordan Alvarez leads Houston at .318 with 31 home runs and 70 RBIs, while Pete Alonso leads Baltimore with 21 home runs and 65 RBIs. Polymarket prices Alvarez at 40c to homer on Saturday, with Alonso at 39c and Gunnar Henderson at 38c.
The pitching matchup mirrors the moneyline. Trevor Rogers takes the ball for Baltimore at 6-7 with a 4.48 ERA; Spencer Arrighetti counters for Houston at 7-5 with a 4.50 ERA, a 0.02-run gap between the starters. Polymarket's strikeout props lean over on both arms, pricing Arrighetti above 4.5 strikeouts at 57c and Rogers above 3.5 strikeouts at 55c.
Below the moneyline, the ladders lean tight. Kalshi prices Baltimore -1.5 at 38c and Houston -1.5 at 33c, giving the road side the slightly better chance of a multi-run win. The total pivots at 8.5 runs: over 8.5 trades at 51c on Kalshi, with over 7.5 at 59c and over 9.5 at 40c. A first-inning run trades at 50c on Kalshi and 48c on Polymarket, and the first-five-innings total of 4.5 runs is the widest cross-platform gap on the board at 52c on Kalshi against 49c on Polymarket.
The line has held. From the opening snapshots Friday evening through the latest tape, Kalshi kept Baltimore at 50c and Houston at 51c without a single tick, while Polymarket moved Baltimore one cent, 50c to 51c. There is no late money to chase; the market watched Friday's one-run game and kept the rematch at even.
When the Orioles vs Astros Market Resolves
The market resolves when Saturday's game goes final. First pitch at Daikin Park is 4:10 PM ET on July 18, 2026, and the moneyline settles to the winning team, paying $1 per share on both Kalshi and Polymarket. Run line contracts settle on the final margin, the total ladder settles on combined runs with extra innings included, and a postponement pushes settlement to the completed game under each platform's rescheduling rules.
Key Orioles vs Astros Catalysts
- Starting pitching: Trevor Rogers (4.48 ERA) against Spencer Arrighetti (4.50 ERA) is a 0.02-run gap, as even as the 50c-51c moneyline it sits under.
- Friday's result: Baltimore won the opener 3-2 and the rematch re-priced at the same coin flip, with no overreaction to a one-run game.
- Home-road splits: Houston is 23-25 at home and Baltimore is 19-26 on the road, weak enough on both sides to cancel out.
- The total at 8.5: over 8.5 runs trades at 51c on Kalshi, a coin flip on the total to match the coin flip on the side.
- Cross-platform inversion: Kalshi leans Houston by 1c and Polymarket leans Baltimore by 1c, so each book quotes the other's favorite as its underdog.
- Power props: Yordan Alvarez (31 home runs) at 40c and Pete Alonso (21 home runs) at 39c to homer are the top slugger prices on Polymarket.
Related Orioles vs Astros Markets
Friday's meeting between these clubs has its own page: the Orioles vs Astros July 17 market closed as the same pickem before Baltimore's 3-2 win. Elsewhere on Saturday's slate, Dodgers vs Yankees is the marquee draw and Rays vs Red Sox carries the AL East angle. The full slate of live game boards sits on the sports prediction markets hub.
Resolution Criteria
Resolves to the team that wins the Baltimore Orioles at Houston Astros game scheduled for 4:10 PM ET on July 18, 2026 at Daikin Park in Houston. Moneyline contracts on the winning team pay $1 per share on Kalshi and Polymarket; the losing side resolves to $0. Run line markets settle on the final margin of victory and total markets settle on combined runs scored, including extra innings. If the game is postponed or suspended, each platform settles once the game is completed under its rescheduling rules.
Key Factors
- Starting pitching: Trevor Rogers (4.48 ERA) vs Spencer Arrighetti (4.50 ERA) is a near-identical matchup, mirroring the 50c-51c moneyline
- Series form: Baltimore took Friday's opener 3-2 and the rematch re-priced at the same coin flip, no overreaction to the one-run result
- Cross-platform inversion: Kalshi leans Houston 51c-50c while Polymarket leans Baltimore 51c-50c, a 1c disagreement in opposite directions
- Total pivots at 8.5 runs: over 8.5 trades at 51c on Kalshi, with the first-five total of 4.5 showing the widest book gap at 52c vs 49c
- Run line lean: Baltimore -1.5 at 38c edges Houston -1.5 at 33c on Kalshi, a slight edge to the road team for a multi-run win
- Power props: Yordan Alvarez (.318, 31 HR) at 40c and Pete Alonso (21 HR) at 39c to homer on Polymarket
What are the current Orioles vs Astros odds?
As of July 18, 2026, the game is a pickem: Kalshi prices Houston at 51c and Baltimore at 50c, while Polymarket prices Baltimore at 51c and Houston at 50c. Neither book has a favorite.
Who is favored in Orioles vs Astros on July 18, 2026?
Nobody. Both sides trade between 50c and 51c, an implied probability of roughly 50% each. The books disagree by a single cent in opposite directions, which is vig, not a lean.
Who are the starting pitchers for Orioles vs Astros?
Trevor Rogers (6-7, 4.48 ERA) starts for Baltimore and Spencer Arrighetti (7-5, 4.50 ERA) starts for Houston on July 18, 2026, per ESPN's probables.
What is the run line and total for Orioles vs Astros?
On Kalshi, Baltimore -1.5 trades at 38c and Houston -1.5 at 33c. The total pivots at 8.5 runs, with over 8.5 at 51c, over 7.5 at 59c, and over 9.5 at 40c.
Where can I trade the Orioles vs Astros market?
The game trades on both Kalshi and Polymarket, with roughly $15K in combined volume as of July 18, 2026. The market settles when the game goes final at Daikin Park.
What should I watch before Orioles vs Astros resolves?
Any pregame move off the 50c-51c line, which held flat through Friday night. Lineup confirmations around Yordan Alvarez and Pete Alonso, and the 4:10 PM ET first pitch on July 18, 2026, are the checkpoints.