Chalk of the Day, August 10: Shohei Ohtani to homer at +225
The chalkiest home run prop on the Monday board, checked against 5,000 play-by-play simulations of Kansas City at the Dodgers. The +225 price implies 30.8%. The simulations say 24.7%. Negative EV at about -20%; it becomes a play at +305 or longer.
Written by Jesse, NegativeEV. Last updated 10 August 2026.
Watch: https://youtube.com/watch?v=RmNcSNslc98
- Sample: 5,000 pitch-by-pitch simulations of one game
- Window: 10 August 2026 slate
- Priced at: +225, read off the board the morning of the game; the earlier snapshot across five books was +202
- Measured: 2026-08-10
Narration on the episode is synthetic, voiced from the written read; the analysis is the simulator's.
The bet
:
| Selection | Shohei Ohtani over 0.5 home runs, KC at LAD |
|---|---|
| Price | +225 (an earlier snapshot across five books had it at +202) |
| The price implies | 30.8% |
| The simulations say | 24.7% |
| Verdict | Negative EV, about -20% |
| Becomes a play at | +305 or longer |
Across 5,000 simulations Ohtani's average is 0.28 home runs and the median is zero: he fails to homer in 75 of every 100 simulated games, homers exactly once in about 22, and twice or more in about 3. The standard error on the number is 0.61 points, so a re-run would not move it far enough to matter. That is a statement about our own noise, not a proof the book is wrong.
What works against him
This is the unusual part of the day, and it is why the prop made the segment: every single thing we track about the opposing pitcher pushes the number down, and none of it is obvious from his line.
Noah Cameron is middle of the pack statistically — a left-hander, 1,959 pitches into the season, ranked against the 547 pitchers with 200 or more. Nothing in his profile says home run suppressor. And yet:
- His career profile is worth 4.1 points. Neutralize it and Ohtani's number rises from 24.7% to about 28.8%.
- His season form is worth another 2.1 points.
- His pitch mix is worth 1.0.
- How long he stays in is worth 0.2.
He releases the ball high (6.13 feet, 90th percentile) and narrow (1.12 feet, 17th percentile) — over the top, from close to the middle of the rubber. Ohtani has never faced him: zero career plate appearances.
Then the thing almost nobody prices:
- Batting at home costs 1.6 points. A home hitter only gets his last trip to the plate if the game needs a bottom of the ninth. Ohtani averages 4.52 trips in these simulations, and the bet turns on which side of five he lands: at five at-bats this is roughly fair value at +225, at six it is comfortably a play. That single inning is most of the disagreement with the price.
- The hitters around him add nothing. Neutralizing the rest of the Dodger order moves the number by 0.03 points — statistically indistinguishable from nothing. He needs them on base to get that extra trip, and right now they are playing league average.
Three more push it down but sit inside the noise threshold, so we would not lean on any of them: his own recent form (1.4 points), the ballpark (2.0) and the weather (1.4). Dodger Stadium ranks 14th of 30 for home runs with a park factor of 1.07 — home runs land on 5.1 of every 100 balls in play in the Dodgers' home games against 4.7 in their road games, same club on both sides. That is a nudge, not a hitter's park.
What works for him
One thing. He is Shohei Ohtani.
His career profile as a hitter is worth 5.7 points over an average bat — the largest single arm on the board today, and larger than anything working against him. Elite home run rate, elite exit velocity, elite launch angle. He has 26 home runs in 467 plate appearances this season, and four in the 46 plate appearances of the last fortnight, so he is not cold either.
That is the entire case. His season form is worth nothing measurable (-0.4 points, inside the error bar), and the man hitting in front of him is worth 0.9.
Why it still grades negative
If you are taking this at +225, you are taking it on Ohtani's talent alone, against a matchup where every measurable piece of the opposition is working the other way and where the ninth inning may never come. Talent is real and it is worth 5.7 points. It is not worth 6.1 points of implied probability on top of everything else.
A bet is not the question of whether the thing might happen. Ohtani homers in roughly a quarter of these simulated games, which is a lot. It is the question of the number next to his name, and +225 pays as though that quarter were nearer a third.
Method
The game is simulated pitch by pitch 5,000 times from the projected lineups, and the prop is graded on how often it lands. 37 factors were neutralized one at a time, each arm a separate 4,000-simulation re-run, so one-at-a-time swings do not sum to the projection; 17 of the 37 came back with a direction we can stand behind. Prices as read off the board the morning of the game; the check is against the quoted price, rake included. This prop is quoted over-only, so there is no two-sided market to strip the book's rake out of — the comparison is our number against what the raw price implies, and some of that gap is the rake itself.
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