Kalshi MLB Home Run Edge Board: Sims HR% Vs Market Price
By Jake Hari
August 4, 2026
Kalshi MLB Home Run Edge Board: Sims HR% Vs Market Price
We built this board because home run markets are the cleanest possible test of a projection engine, one hitter, one night, one yes/no question. Kalshi prices that question in cents for dozens of hitters every day. Stokastic's Sims answer the same question from simulated at-bats. We put every listed hitter side by side, rank the disagreements, and grade our own numbers against settlement, every single day.
The Quick Answer
Kalshi's MLB home run contracts pay $1.00 if the named hitter goes deep, and the price in cents reads as the market's probability. The Sims produce their own home run probability for every hitter from thousands of simulated games with tonight's real starters. The full board below ranks every matched hitter by the gap between those two numbers, and the graded record of every past gap sits one link away.
The Full Board
Fetched August 4, 2026 at 12:01 PM ET — 22 Kalshi-listed hitters matched to Sims projections.
| Hitter | Team | Sims HR% | Kalshi Mid | Gap | Book (bid/ask) |
|---|---|---|---|---|---|
| Vladimir Guerrero Jr. | TOR vs HOU | 19.8% | 11.5c | +8.3 | 11c / 12c |
| Cal Raleigh | SEA vs DET | 23.9% | 19.5c | +4.4 | 19c / 20c |
| Shohei Ohtani | LAD vs CHC | 31.8% | 27.5c | +4.3 | 27c / 28c |
| Mookie Betts | LAD vs CHC | 16.6% | 12.5c | +4.1 | 12c / 13c |
| Manny Machado | SD vs ARI | 19.0% | 15.5c | +3.5 | 15c / 16c |
| Rafael Devers | SF vs TEX | 13.6% | 16.5c | -2.9 | 16c / 17c |
| Fernando Tatis Jr. | SD vs ARI | 16.0% | 13.5c | +2.5 | 13c / 14c |
| Jackson Merrill | SD vs ARI | 12.9% | 10.5c | +2.4 | 10c / 11c |
| Christian Walker | HOU vs TOR | 16.7% | 14.5c | +2.2 | 14c / 15c |
| Ronald Acuña Jr. | ATL vs MIA | 15.5% | 17.5c | -2.0 | 17c / 18c |
| Julio Rodríguez | SEA vs DET | 17.5% | 15.5c | +2.0 | 15c / 16c |
| Alex Bregman | CHC vs LAD | 12.4% | 10.5c | +1.9 | 10c / 11c |
| Jonathan Aranda | TB vs COL | 13.6% | 15.5c | -1.9 | 15c / 16c |
| Junior Caminero | TB vs COL | 26.0% | 24.5c | +1.5 | 24c / 25c |
| Corbin Carroll | ARI vs SD | 14.1% | 15.5c | -1.4 | 15c / 16c |
| Pete Crow-Armstrong | CHC vs LAD | 13.6% | 12.5c | +1.1 | 12c / 13c |
| Randy Arozarena | SEA vs DET | 14.4% | 13.5c | +0.9 | 13c / 14c |
| Yordan Alvarez | HOU vs TOR | 23.7% | 24.5c | -0.8 | 24c / 25c |
| Ketel Marte | ARI vs SD | 13.7% | 14.5c | -0.8 | 14c / 15c |
| Freddie Freeman | LAD vs CHC | 15.1% | 14.5c | +0.6 | 14c / 15c |
| Matt Olson | ATL vs MIA | 21.1% | 21.5c | -0.4 | 21c / 22c |
| Bobby Witt Jr. | KC vs MIN | 17.7% | 17.5c | +0.2 | 17c / 18c |
For example, the widest gap on the board fetched August 4, 2026 at 12:01 PM ET: Vladimir Guerrero Jr. (TOR vs HOU). The Sims put his 1+ home run probability at 19.8%, while the Kalshi book sat at 11c bid / 12c ask, a 11.5c mid that reads as a 11.5% market probability — 8.3 points higher than the market. That row enters the ledger today and grades itself when the contract resolves Yes or No tonight.
Settlement is mechanical: a 1+ home run contract resolves Yes the moment the hitter's first home run of the game is official, and resolves No when the game ends without one. That is the entire contract, which is why we trust these markets as a grading source for our own simulations.
Reading it: Sims HR% is the simulated probability of at least one home run today. Kalshi Mid is the midpoint of the live bid and ask on the 1+ home run contract, in cents, which reads directly as the market's probability. Gap is Sims minus market, so positive rows are hitters the Sims like more than the price does, and negative rows are hitters the market is paying for more than the simulations support.
The Record
Grading begins with tomorrow's edition — every gap published today is recorded and graded against Kalshi settlement, win or lose, on the Sims vs Kalshi ledger.
The bar we hold ourselves to: every gap of four points or more that appears on this board gets recorded the day it publishes and graded against Kalshi's settlement, hit or miss. A projection page without a public record is an opinion page. The Sims vs Kalshi ledger is the record.
Why Gaps Exist At All
Prediction markets are good, and most rows on most days show the Sims and the market within a few points of each other, which is mutual confirmation, not a failure of either side. The interesting rows come from the places a simulation engine and an order book work differently. The Sims re-run when lineups confirm, so a late scratch or an unexpected platoon start can move a simulated HR probability before casual money moves the contract. Ballpark and starter handedness are priced into the simulation at the at-bat level, while a market price leans on traders noticing the same thing. And thin books drift: a home run contract that has not traded since morning can sit at a stale price while the Sims moved at lineup lock.
None of that makes the Sims automatically right. The market catches things simulations cannot, injuries whispered before they are announced, a starter tipping pitches, weather shifting an hour before first pitch. That is exactly why the board is graded instead of celebrated: over a season, the record tells you which side of a gap deserved your attention, market by market, in numbers anyone can check.
Use It With The Games Page
The Kalshi MLB picks page runs every day alongside this board with the game-level view: projected team runs against Kalshi's two-sided game prices, plus the day's top five home run gaps in summary. And if the simulated probabilities themselves are what you want, hitter by hitter with projections and ownership, that is the Stokastic MLB Sims, the engine this entire board is built from. New to exchange pricing? Our sister site's Kalshi guide covers contracts, spreads, and settlement in plain language.
FAQ
What is this board? Every Kalshi-listed MLB home run hitter, daily, with the Sims' simulated HR probability next to the live contract price, ranked by gap.
Where does the Sims number come from? Stokastic's slate simulations, thousands of simulated games with confirmed lineups and tonight's starters. It is the same engine behind our DFS projections.
What does the gap mean? The size of the disagreement between simulation and market, in probability points. Both directions get published and both get graded.
Is this betting advice? No. It is a documented, graded comparison between a projection engine and a market. The record of how those comparisons settle is public.
Nothing on this page is betting advice. Kalshi event contracts are CFTC-regulated event derivatives; a position can lose its full value. 18+; availability is state-specific. Prices reflect their stamped fetch time and move all day.