Chalk of the Day, August 27: Alvarez to homer at +230

The chalkiest home run prop on the Thursday board, checked against 5,000 play-by-play simulations of the Astros at the Yankees. The +230 price implies 30.3%. The simulations say 20.5%. Negative EV at about -32%; it becomes a play at +388 or longer.

Written by Jesse, NegativeEV. Last updated 27 August 2026.

• Sample: 5,000 pitch-by-pitch simulations of one game
• Window: 27 August 2026 slate
• Priced at: +230 at Bovada, as quoted off the board at publication
• Measured: 2026-08-27

The bet

The check:

This is the most-bet home run prop on Thursday's board, and the simulations disagree with the price on it. 7 games had odds, 5 of the chalkiest selections were graded against the sims, and the verdicts came back 3 Negative EV, 1 Roughly Fair, 1 Positive EV. Nobody here is picking anything. This is a price the public is already taking, checked.

The board ran from +204 to +266 on this prop across 7 books at the time of the check. Every one of those prices is short of +388, 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 Alvarez's average is 0.23 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 2.1 in every 100 of them.

At 5,000 simulations that 20.5% carries a standard error of 0.57 points, so 95 runs in 100 would land between 19.4% and 21.6%. The gap to the price is about 10 points, roughly 17 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

How often Alvarez comes to the plate moves this number as much as anything about his swing. Across the runs he comes up 4.48 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 5.1% 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

Two arms clear their own noise on this side, and together they are the story.

• His own career profile, who he is as a hitter, props the number up by about 7.0 points. Neutralize it and 20.5% becomes 13.5%. HR rate .073, 13 of 318 hitters, top 10%. BABIP .319, 55 of 318 hitters, top quarter. K rate .180, 79 of 318 hitters, top quarter. Exit velo 93.9, 6 of 318 hitters, top 10%. Launch angle 17, 267 of 318 hitters.
• The weather props the number up by about 2.3 points. Neutralize it and 20.5% becomes 18.2%. That arm neutralizes temperature, wind and conditions at once, so the cause is not separable. It is 76 degrees with a 9 mph wind blowing right to left.

The pitcher

A right-hander, 1,343 pitches into the season and ranked against the 576 pitchers with enough of them to compare. He releases from a three-quarters slot, 5.68 feet up (53th percentile) and 1.98 feet across (64th), with 6.25 feet of extension (31th percentile).

The ballpark

Yankee Stadium ranks 2nd of 30 for home runs, with a park factor of 1.35 where 1.00 is neutral. It is one of the friendlier parks to hit one in. In the 2026 data home runs land on 5.8 of every 100 balls in play in the Yankees' home games against 4.2 in their road games, 2,156 batted balls at home, 3,107 away, the same club on both sides of the split, so what is left is the park. Open roof, grass, 318 feet to left, 408 to centre, 314 to right, 55 feet of elevation. Tonight it is 76 degrees with a 9 mph wind blowing right to left.

Yordan Alvarez, recent against season:

• usual lineup spot: 2nd (over 129 games)
• plate appearances this season: 539
• 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 8.93 total runs. His side scores 5.71 when the homer lands against 3.91 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 +230 the price is asking for more than the simulations produce. It does not say he will not homer. He goes deep in 20 of every 100 simulated games. Every play is relative to its price, and the two numbers meet at +388.

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. Those 37 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 37 came back with a direction we can stand behind. The price is +230 as quoted at Bovada at publication, and the check is against that quoted price, rake included.

Inside the noise floor

26 of the 37 arms sit inside their own noise, including his own recent form (+2.2), Gerrit Cole's career profile, the pitcher he faces (+0.3), how long Gerrit Cole stays in (+0.1), the ballpark (-1.7), his own season form (-1.7), Gerrit Cole's season form (-1.1), playing on the road, he is on the AWAY side, so he is guaranteed all nine innings (-0.6), what Gerrit Cole has been throwing lately, his pitch mix (-0.5), the rest of the order, the other eight, without him (-0.5). 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.

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