The Quick Answer
Kalshi's home run board for the Aug. 31 Brewers at Cubs game made Pete Crow-Armstrong the favorite at 24¢, and most of the money followed him to the Cubs side. The pitching matchup said the market had the right team and maybe the wrong Cub.
Brewers starter Kyle Harrison had given up 14 home runs on the season, and 13 of them went to right-handed hitters. Crow-Armstrong bats left. Seiya Suzuki, a right-handed bat priced at 20¢, was the one hitter whose split lined up on both sides of the matchup.
The game has been played and every contract below has settled. What follows is the board as it stood on the morning of Aug. 31, kept as the record of what the market believed before first pitch and why.
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Why Three-Quarters of the Money Sat on the Cubs
The board priced two different baseball games. The Cubs hitters faced Harrison, a good left-hander with one very specific leak. The Brewers hitters faced Clay Holmes, a right-hander who had allowed 4 home runs all season. Roughly three-quarters of the contracts traded by the morning snapshot sat on Cubs hitters, so the real argument was never Brewers versus Cubs. It was which Cub.
The Board: 14 Home Run Markets (Snapshot 9:54 a.m. ET, Aug. 31)
Each of the seven hitters had a yes/no contract on hitting one or more home runs, plus a longshot contract on two or more.
| Market | Team | Bid | Ask | Last | Volume |
|---|---|---|---|---|---|
| Pete Crow-Armstrong 1+ HR | Cubs | 23¢ | 24¢ | 24¢ | 51,616 |
| Seiya Suzuki 1+ HR | Cubs | 19¢ | 20¢ | 20¢ | 44,848 |
| Jackson Chourio 1+ HR | Brewers | 17¢ | 18¢ | 18¢ | 32,269 |
| Alex Bregman 1+ HR | Cubs | 15¢ | 16¢ | 16¢ | 50,604 |
| Michael Busch 1+ HR | Cubs | 14¢ | 15¢ | 15¢ | 54,625 |
| William Contreras 1+ HR | Brewers | 14¢ | 15¢ | 14¢ | 42,711 |
| Brice Turang 1+ HR | Brewers | 10¢ | 11¢ | 11¢ | 11,145 |
| Pete Crow-Armstrong 2+ HR | Cubs | 2¢ | 4¢ | 4¢ | 46,187 |
| Seiya Suzuki 2+ HR | Cubs | 2¢ | 3¢ | 2¢ | 15,479 |
| Jackson Chourio 2+ HR | Brewers | 0¢ | 2¢ | 2¢ | 1,399 |
| Alex Bregman 2+ HR | Cubs | 0¢ | 2¢ | 2¢ | 1,087 |
| Brice Turang 2+ HR | Brewers | 0¢ | 2¢ | 1¢ | 519 |
| William Contreras 2+ HR | Brewers | 0¢ | 2¢ | 2¢ | 372 |
| Michael Busch 2+ HR | Cubs | 0¢ | 2¢ | 2¢ | 31 |
Prices and volume captured 9:54 a.m. ET, Monday, Aug. 31, hours before lineups. About 353,000 contracts had traded by then. All markets have since settled.
The strange row was not the favorite. Crow-Armstrong 2+, a two-homer ticket at 2¢/4¢, had traded 46,187 contracts, more than Suzuki's entire 1+ market. That is a fan base pricing its favorite player's ceiling, not handicapping. Michael Busch's 1+ market was the most-traded on the event despite sitting fifth by price, so the 15¢ area, not the favorite, was where the crowd did most of its arguing.
The Cubs Side: Harrison's Split Pointed at Suzuki
Harrison had a good season, a 2.79 ERA, but home runs were the bill he kept paying: 14 allowed, 13 of them to right-handed hitters and 1 to a lefty. Same-handed hitters barely touched him. Opposite-handed hitters saw everything.
Suzuki was the cleanest case on the board. A right-handed bat with 23 homers on the season and a .547 slugging percentage against left-handed pitching, facing the exact hand Harrison's leak pointed at. At 20¢ he carried that case quietly while the board's attention sat elsewhere.
Alex Bregman's 16¢ leaned on reputation. He owned an .804 OPS against lefties this year, but his 5.2% barrel rate was the weakest contact profile in the board's top tier. The price carried the name. The batted-ball data was less enthusiastic.
Crow-Armstrong bats left, the side Harrison had allowed one homer to all year. He was 24¢ anyway because his season erased platoon logic: 38 home runs, and a .580 slugging percentage against lefties that ran higher than his mark against righties. A hitter without a platoon problem against a pitcher who had been a platoon fortress. The price was the market netting those two facts out.
Michael Busch, the other lefty, got no such override. Nothing in his profile suspended the Harrison rule the way Crow-Armstrong's raw power did, and that was the whole gap between 15¢ and 24¢.
The Brewers Side: Holmes Kept the Ball on the Ground
Holmes had allowed 4 home runs across 75.2 innings between the Mets and the Cubs, with a 5.4% barrel rate allowed and a below-average strikeout rate. Ground balls, weak contact, nothing in the air. The Brewers prices read like the market did that homework.
Jackson Chourio's 18¢ was the crowd refusing to fully punish a 20-homer right-handed bat for the matchup. William Contreras at 15¢ was thinner than it looked, with a 7.9% barrel rate and little power against right-handed pitching.
Brice Turang at 11¢ was the mirror image of the Crow-Armstrong problem. Nearly all of his 17 home runs came against right-handers, but Holmes had allowed 3 homers to left-handed bats all season. A hitter's split can check its box while the pitcher's box stays unchecked.
The whole board fits on one ledger: each hitter's 2026 power against that night's pitching hand, next to what that night's starter had actually given up to that side.
| Hitter | Bats | 2026 vs tonight's hand (HR / AB, SLG) | Starter's HR allowed to that side |
|---|---|---|---|
| Pete Crow-Armstrong | L | 11 / 169, .580 vs LHP | Harrison: 1 in 115 AB to LHB |
| Seiya Suzuki | R | 7 / 117, .547 vs LHP | Harrison: 13 in 277 AB to RHB |
| Alex Bregman | R | 5 / 126, .421 vs LHP | Harrison: 13 in 277 AB to RHB |
| Michael Busch | L | 6 / 151, .404 vs LHP | Harrison: 1 in 115 AB to LHB |
| Jackson Chourio | R | 14 / 299, .468 vs RHP | Holmes: 1 in 107 AB to RHB |
| William Contreras | R | 10 / 352, .398 vs RHP | Holmes: 1 in 107 AB to RHB |
| Brice Turang | L | 16 / 348, .500 vs RHP | Holmes: 3 in 167 AB to LHB |
Splits: 2026 season through Aug. 31, via MLB's stats API.
Read across Suzuki's row and both boxes check. Read across Turang's and only the left one does. Only one hitter paired a .500-plus slugging split with a starter who leaked homers to his side, and it was not the favorite.
The Wrigley Wildcard
Wrigley Field is the most wind-dependent park in baseball, and the flags do more to its daily character than any static park factor. The Aug. 31 forecast called for mid-80s heat at first pitch and a light southwest breeze, which on Wrigley's northeast-facing diamond blows out toward center and right. Warm air and an outward flag are the conditions under which the park adds carry.
That was context, not an angle. Traders on the exchange could read a forecast too, and it helps explain why hitters facing elite pitching still went for 11¢ to 24¢ rather than lower.
How These Contracts Settled
Each contract paid $1.00 if the hitter homered and zero if he did not, so the ask in cents was the crowd's stated probability. The rule that separates a Kalshi home run contract from a sportsbook prop is the scratch rule: a hitter left out of the lineup does not get refunded.
Kalshi's rule, verbatim"If [the player] is scratched or not included in the starting lineup, the market will resolve to the fair market price." Same if he starts but never records a plate appearance — and pinch-hit at-bats don't count for a player who enters mid-game.
That is why the fine print on a late-afternoon lineup card was part of every price bought that morning.
New York's attorney general sued Kalshi on July 31 alleging it operates as an unlicensed gambling platform, and that fight is pending. We track where prediction markets stand legally; check your state before you trade.
Bottom Line
The market had the right half of the board and arguably the wrong Cub. Harrison's split argued for Suzuki over the favorite, Holmes' season argued against all three Brewers, and the Wrigley wind was the one thing no split could price. When Kalshi lists the next Brewers-Cubs board, the starter's platoon split and the flags are the first two things to check. For the sportsbook side of the same question, today's MLB home run picks board argues the day's best-priced plays case by case.
