Chalk of the Day, August 19: Schwarber to homer at +215

The chalkiest home run prop on the Wednesday board, checked against 5,000 play-by-play simulations of the Marlins at the Phillies. The +215 price implies 32.5%. The simulations say 27.6%. Negative EV at about -13%; it becomes a play at +263 or longer.

Written by Jesse, NegativeEV. Last updated 19 August 2026.

• Sample: 5,000 pitch-by-pitch simulations of one game
• Window: 19 August 2026 slate
• Priced at: +215 at Fanatics, as quoted off the board at publication
• Measured: 2026-08-19

The bet

The check:

This is the most-bet home run prop on Wednesday's board, and the simulations disagree with the price on it. 14 games had odds, 19 of the chalkiest selections were graded against the sims, and the verdicts came back 12 Negative EV, 3 Roughly Fair, 4 Positive EV. Nobody here is picking anything. This is a price the public is already taking, checked.

The board ran from +200 to +217 on this prop across 4 books at the time of the check. Every one of those prices is short of +263, so where you shop changes how much this costs you, not whether it costs you.

This prop is quoted over-only, so there is no two-sided market to strip the book's rake out of. The honest comparison is the simulated number against what the quoted price implies, and some of that gap is the rake itself.

What the simulations did

Across 5,000 simulations Schwarber's average is 0.31 home runs and the median is 0. The most common outcome by a distance is none at all.

The shape of 5,000 simulations:

The anytime line pays the same for all of the multi-homer games, and there are 3.7 in every 100 of them.

At 5,000 simulations that 27.6% carries a standard error of 0.63 points, so 95 runs in 100 would land between 26.3% and 28.8%. The gap to the price is about 4 points, roughly 7 times that error bar. Said narrowly, and it should be said narrowly: that means only that re-running the simulator would not move the number far enough to reach the price. It is not a claim that we are right and the book is wrong. A number that is systematically off is off to as many standard errors as you like.

How many cracks he gets

Schwarber bats on the home side, which cuts the other way here: his last trip only happens if the game needs a bottom of the ninth, and it does not always need one. Across the runs he comes up 4.49 times on average, at-bats plus walks, and the home run number moves with that count.

Trips to the plate, and what each one is worth:

Pooled across every simulation he goes deep on 7.0% of his trips, so whether he bats one more time or one fewer is worth more here than any read on his swing. That extra trip is not his to take either. It depends on the eight hitters around him keeping the order moving, and in the simulations they do not always do it.

What works for him

• His own career profile, who he is as a hitter, props the number up by about 10.2 points. Neutralize it and 27.6% becomes 17.4%. HR rate .096, 3 of 306 hitters, top 10%. BABIP .257, 286 of 306 hitters, bottom 10%. K rate .298, 282 of 306 hitters, bottom 10%. Exit velo 93.3, 7 of 306 hitters, top 10%. Launch angle 18.5, 276 of 306 hitters.

What works against him

• Playing at home takes about 1.4 points off. Neutralize it and 27.6% becomes 29.0%. His last trip only happens if the game needs a bottom of the ninth, and it does not always need one.

The pitcher

A right-hander, 2,570 pitches into the season and ranked against the 565 pitchers with enough of them to compare. He releases from a three-quarters slot, 5.78 feet up (63th percentile) and 1.72 feet across (49th), with 6.04 feet of extension (15th percentile).

The ballpark

Citizens Bank Park ranks 9th of 30 for home runs, with a park factor of 1.16 where 1.00 is neutral. It is one of the friendlier parks to hit one in. In the 2026 data home runs land on 5.4 of every 100 balls in play in the Phillies' home games against 4.6 in their road games, 2,616 batted balls at home, 2,812 away, the same club on both sides of the split, so what is left is the park. Open roof, grass, 329 feet to left, 401 to centre, 330 to right, 20 feet of elevation. Tonight it is 86 degrees with an 8 mph wind blowing left to right.

Kyle Schwarber, recent against season:

• usual lineup spot: 2nd (over 118 games)
• plate appearances this season: 525
• plate appearances in the recent window: 20

Those are the inputs the simulator was served, not a separate stat source.

The rest of his night

The home run does not arrive alone. Split across the 5,000 simulations on whether it lands:

:

The game itself averages 8.19 total runs. His side scores 5.32 when the homer lands against 3.90 when it does not, so this is not an isolated event - it travels with the whole offence.

What this does and does not say

It says that at +215 the price is asking for more than the simulations produce. It does not say he will not homer. He goes deep in 28 of every 100 simulated games. Every play is relative to its price, and the two numbers meet at +263.

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. 38 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. Those 38 cover everything that could bear on this hitter rather than every factor in the game: the other hitters' own career, season and recent tiers were skipped on purpose, because they are most of the cost and none of the answer for a prop about one man. 11 of the 38 came back with a direction we can stand behind. The price is +215 as quoted at Fanatics at publication, and the check is against that quoted price, rake included.

Inside the noise floor

27 of the 38 arms sit inside their own noise, including Sandy Alcantara's season form (+2.0), what Sandy Alcantara has been throwing lately, his pitch mix (+1.6), the rest of the order, the other eight, without him (+0.9), the ballpark (+0.6), how long Sandy Alcantara stays in (+0.1), the weather (-1.9), his own season form (-1.6), batting 1st today instead of his usual spot (-1.3), his own recent form (-0.7), Sandy Alcantara's career profile, the pitcher he faces (-0.4). Those numbers are real measurements and they are printed rather than dropped, but at this simulation count the arm cannot tell a small real effect from no effect. So none of them does nothing, and none of them can be named the thing driving this.

Written up for readers: https://negativeev.com/about/home-run-props All findings: https://negativeev.com/research