Chicago White Sox vs Chicago Cubs Prediction Market Odds, August 18, 2026
| Spread | Total | ML | Best ML | |
|---|---|---|---|---|
â–¶Sox | +2.5 69%80% | O 9.5 41%41% | 21%20% | 21% Kalshi |
â–¶Cubs | -2.5 31%20% | U 9.5 59%59% | 41%38% | 41% Kalshi |
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The Chicago Cubs are the 61c favorite over the Chicago White Sox for game two of the crosstown series at Wrigley Field on August 18, 2026, priced at exactly 61c on both Kalshi and Polymarket. That is a soft number for a 72-53 home club, and it reflects Kevin Gausman (6-11, 4.53 ERA) taking the ball against a White Sox team that is 65-58, first in the AL Central, and winners of three straight. The White Sox also lead the 2026 season series 2-1. The board carries roughly $5.6K in lifetime volume across the two platforms, with the live prices on the board above.
Chicago plays Chicago again on Tuesday, and the two books agree to the cent: the Cubs are 61c on Kalshi and 61c on Polymarket, with the White Sox at 39c and 40c. The Cubs (72-53) sit second in the NL Central, 5.0 games back of the division lead but 5.5 games clear in the wild card race. The White Sox (65-58) arrive in first place in the AL Central on a three-game winning streak. Both clubs are 6-4 over their last ten. The board has traded roughly $5.6K in lifetime volume across Kalshi and Polymarket, with about $2.0K of that sitting on each side of the moneyline.
White Sox vs Cubs Market Context
Kevin Gausman starts for the Cubs at 6-11 with a 4.53 ERA, a line that explains why the home price is 61c instead of the high 60s. The White Sox had not posted a probable starter as of publication, which is the single largest open variable on this board. When a pitching matchup is half-known, the moneyline tends to sit closer to the season-long team strength than to the day's edge, and that is what 61c represents here.
The records argue for a wider number than the market is offering. The Cubs are 36-26 at Wrigley Field and carry a plus-100 run differential (645 scored, 545 allowed). The White Sox are 28-34 on the road with a plus-47 differential (594 scored, 547 allowed). Nineteen games separate them in the standings column, and yet the price gap is only 21.5c on the two-way. Recent form is the reason. The Cubs dropped two of three at home to St. Louis, losing 8-4 and 11-4 after a 3-0 win, while the White Sox swept Detroit on the road by scores of 9-5, 4-3 and 7-5. The White Sox also took two of three from the Cubs in the May meetings and lead the season series 2-1.
The cross-platform read is flat, and that matters. A 0c gap on the Cubs and a 1c gap on the White Sox sits inside normal book noise, so there is no better price to hunt on the moneyline tonight. Movement has been quiet too: the Cubs traded at 62c on Kalshi during the Monday evening session and sit at 61c now, a one-cent drift on roughly $1.7K of 24-hour Kalshi volume. This line has held.
Availability is thinner on both rosters than the records suggest. The Cubs are without Matt Shaw (10-day injured list, hand) and three bullpen arms in Hunter Harvey, Riley Martin and Hoby Milner. The White Sox are down Davis Martin (15-day injured list, finger), Chris Murphy, Drew Thorpe and Ky Bush, a rotation and relief group that is why the probable starter is still open. Pete Crow-Armstrong leads the Cubs at .276 with 28 home runs and 75 RBIs. Miguel Vargas matches him with 28 home runs and 72 RBIs for the White Sox, and Chase Meidroth leads that lineup at .278.
What the White Sox vs Cubs Spread and Total Imply
The most-traded non-moneyline line on the board is the 9.5 total, with the Over at 44.5c (43c Kalshi, 46c Polymarket) on about $1.8K of lifetime volume. That 3c split is the widest cross-platform disagreement anywhere on this game, and it is the only line where the two books are pricing meaningfully different run environments. Over 10.5 is 35c on both platforms and Over 11.5 is 26.5c, a ladder that puts the market's central expectation a shade under ten runs at Wrigley.
The run line reads the same way. Cubs -1.5 is 42.5c (42c Kalshi, 43c Polymarket) against a 61c moneyline, so the market is charging 18.5c for the difference between winning and winning by two or more. That is the standard shape for a modest home favorite rather than a laugher. White Sox -1.5 sits at 30.5c and Cubs -2.5 at 32c. The first-inning market, which asks whether either side scores in the opening frame, is 53.5c (54c Kalshi, 53c Polymarket), the tightest paired line on the board.
When the White Sox vs Cubs Market Resolves
First pitch is 7:05 pm Central on Tuesday, August 18, 2026 at Wrigley Field, the second game of a three-game crosstown series that closes on Wednesday afternoon. The moneyline resolves to the team that wins the game, with no draw outcome in baseball. The run line and the totals settle on the final score including extra innings. Both Kalshi and Polymarket settle once the game is official and the result is final on the scheduled date.
Key White Sox vs Cubs Catalysts
- The unnamed White Sox starter: the largest single price-mover on this board, with Chicago's rotation carrying four arms on the injured list.
- Kevin Gausman's form: a 4.53 ERA and a 6-11 record are why the Cubs are 61c and not 68c at home.
- Cross-platform value on the total: Polymarket has the Over 9.5 at 46c against Kalshi's 43c, the only 3c split on the game.
- Wrigley wind and the run environment: the 9.5 total at 44.5c and the 10.5 at 35c leave the market slightly under ten runs, so conditions move this line first.
- Divisional stakes on both sides: the White Sox lead the AL Central and the Cubs hold a 5.5-game wild card cushion, so neither club is resting regulars.
- Series momentum: the White Sox took two of three in May and lead the 2026 season series 2-1 despite the 19-game record gap.
Related White Sox vs Cubs Markets
The series opener is priced on its own board at White Sox vs Cubs on August 17, which is the cleanest comparison for how this matchup has been valued day over day. The standings context trades separately: the White Sox lead is priced in the AL Central division market and the Cubs chase in the NL Central division market. For the October question, see Cubs playoff odds, White Sox playoff odds and the 2026 World Series market. Full team boards live at the Chicago Cubs hub and the Chicago White Sox hub.
Resolution Criteria
Resolves to the team that wins the Chicago White Sox at Chicago Cubs game scheduled for 7:05 pm Central on August 18, 2026 at Wrigley Field. The moneyline pays $1 per share on the winning team and $0 on the loser, with no draw outcome. Run line contracts settle on the final margin including extra innings, and total contracts settle on combined runs scored by both teams in the full game. If the game is suspended and completed on a later date, both platforms settle on the completed official result. If the game is postponed and not played, or is called before it becomes an official game, contracts void and refund per each platform's rain-out and postponement rules.
Key Factors
- White Sox probable starter unannounced with four pitchers on the injured list (largest single price-mover)
- Kevin Gausman at 6-11 with a 4.53 ERA holding the Cubs price at 61c instead of the high 60s
- Polymarket Over 9.5 at 46c versus Kalshi at 43c, the only 3c cross-platform split on the board
- Wrigley Field run environment against a 9.5 total priced at 44.5c and a 10.5 total at 35c
- White Sox three-game winning streak and 2-1 lead in the 2026 season series
- Divisional stakes with the White Sox first in the AL Central and the Cubs 5.5 games clear in the wild card
What are the current White Sox vs Cubs odds?
As of August 18, 2026, the Chicago Cubs are the 61c favorite (61c on Kalshi, 61c on Polymarket) and the Chicago White Sox are 39.5c (39c Kalshi, 40c Polymarket). The live board above carries the current prices.
Who is favored in White Sox vs Cubs and by what implied probability?
The Cubs are favored at a 61% implied probability against roughly 39.5% for the White Sox. That is a narrow edge for a home team that is 36-26 at Wrigley Field against a road club that is 28-34 away from home.
Where can I trade the White Sox vs Cubs market?
Both Kalshi and Polymarket list this game, with the moneyline, run line, game total and a first-inning run market on each. The board has traded roughly $5.6K in lifetime volume across the two platforms.
When does the White Sox vs Cubs market resolve?
First pitch is 7:05 pm Central on Tuesday, August 18, 2026 at Wrigley Field. Contracts settle once the game is final and official, normally within a few hours of the last out.
What is the White Sox vs Cubs total?
The primary total is 9.5 runs, with the Over at 44.5c (43c Kalshi, 46c Polymarket). Over 10.5 trades at 35c and Over 11.5 at 26.5c, putting the market's central expectation just under ten combined runs.
What should I watch before White Sox vs Cubs starts?
The White Sox probable starter, which was still unannounced as of publication with Davis Martin, Chris Murphy, Drew Thorpe and Ky Bush all on the injured list. Wind conditions at Wrigley Field are the second item, since the 9.5 total at 44.5c moves faster than the moneyline.