Fantasy Baseball: No, you shouldn't be worried about Home Run Derby participants like Shohei Ohtani

The Home Run Derby curse. Or maybe it's a hangover? Whatever you call it, it's one of those tropes among baseball fans that comes up every season. Fans don't want players on their favorite teams to participate in the derby lest it wreck their swings and ruin their seasons. With Shohei Ohtani, Joey Gallo, Juan Soto and others headlining this year's class, there's a lot at stake if that were to happen.

Many Fantasy players surely have the same concerns, but I don't share those concerns at all. To show why, I looked back at every home run derby participant since 2003, comparing their first half to their second-half performance, as well as to their previous season's performance. After limiting it to players who had at least 250 PA before the break, 200 after, and at least 350 in the previous season, I was left with 117 player seasons among the derby participants.

Among those 117 players, they collectively hit .295/.379/.558 before their Home Run Derby performance, compared to .283/.371/.512 after. That's not some incredible drop in performance, but you'd certainly notice an 8% reduction in power production from Ohtani, right?

So, case closed, right? The derby ruins swings and you should be very worried if you have one of the participants on your team, right?

Not exactly. Because, if you compare a player's post-ASB performance to his previous season, there's effectively no difference:

	AVG	OBP	SLG	HR/PA
Pre-derby	0.295	0.379	0.558	5.58%
Post-derby	0.283	0.371	0.512	4.65%
Previous season	0.283	0.364	0.515	4.74%

At the population level, at least, there doesn't really seem to be any kind of post-derby hangover at all. What it looks like is, well, rather obvious: Players who get selected for the Home Run Derby (and All-Star Game) are generally having a very, very good first half, especially relative to their established baselines.

That's not to say all players in the derby will regress in the second half, or there won't be some who struggle mightily after the derby. There have been 10 players who have improved their OPS by .100 or more after the Derby. That's not nothing! That'll probably happen this year, too.

But it's a lot more likely that a player will decline; 13 out of 117 players in the sample saw their OPS decline by more than .200 following the derby, and 24 saw it decline at least .150. Some of these probably stand out in your memory: Mark Trumbo in 2012, Todd Frazier in 2015, Bobby Abreu in 2005. Of course, it's worth remembering that every one of those 24 with the exception of Abreu in 2005 was performing better than they had in the previous season, including 14 who were at least .100 ahead of that previous season in the first half.

That isn't necessarily proof that the derby can't mess with a player's performance. It's just one more thing a player has to expend energy on during a long season, and there have been at least anecdotal accounts from players about how the derby messed with their swings. But, when trying to predict performance, there's not really much reason to believe participating in the derby is an especially important factor to consider.

Which is to say, yeah, the guys participating in the derby Monday night will probably not be as good in the second half as they were in the first. But that isn't because of the derby. It's because, as a general rule, you should expect most players who perform a lot better in a smaller sample size than their established baseline will move back in the direction of that baseline.

Of course, figuring out which players are more likely to regress and which aren't is a big part of playing Fantasy Baseball well, so let's take a look at the eight participants in this year's derby and see which ones might be in for a second half letdown:

Shohei Ohtani - Chance of a letdown: 65%

From a performance standpoint, I think Ohtani is mostly legitimate -- he really does have some of the best power in the game. I'll take the under on a 1.062 OPS the rest of the way, but my real concern is mostly injury related. Ohtani is always going to be at a higher risk of suffering an injury than most position players because he isn't just a position player. He also carries the occupational risk that comes along with throwing a baseball as hard as you can 100 times every six days. I think Ohtani is a sell-high candidate, but he's also so much fun to have on your team that I can't exactly recommend selling him, if that makes sense.

Matt Olson - Chance of a letdown: 50%

Whether Olson continues to be an elite hitter ultimately comes down to one thing: Whether he can keep hitting this well against left-handed pitching. For his career, Olson has an OPS .109 higher against righties than lefties, but that's been flipped this season. He has 11 of his 23 homers against lefties and he has a 21.1% strikeout rate against them; he had a 27.0% K rate against them in the prior two seasons. If these improvements stick, he's a completely different hitter, one of the best in the game. He's the consensus No. 3 first baseman among all three Fantasy Baseball Today analysts, so we're buying in.

Joey Gallo - Chance of a letdown: 50%

It's worth keeping in mind, Gallo was hitting just .214 with a .764 OPS as of June 19, and was viewed as one of the bigger disappointments from his tier in Fantasy. He's been absurdly hot since, hitting 13 homers in his past 18 games to get his numbers to where they are -- a much more respectable .239/.402/.522 triple-slash with 24 homers. All of a sudden, he's not far off where he was in 2019 before injuries derailed his season, and he's doing much better than he did in a disastrous 2020. Gallo does have his best strikeout rate ever this season, which is a great sign, but his expected stats don't quite match what he's done to date. Gallo is an incredible power hitter who should be a must-start Fantasy option moving forward, but he's also an incredibly streaky hitter, someone who could absolutely carry your team down the stretch but who could also slump at the worst possible time. He's probably a sell-high candidate because his value has probably peaked, but it's not like I'm expecting the bottom to fall out if you don't.

Salvador Perez - Chance of a letdown: 45%

Perez has played 126 games over the past two seasons and has 33 homers, 85 RBI and 63 runs scored, which is pretty exceptional for a catcher. Especially a catcher who has nearly 50 more plate appearances than anyone else at the position. The surface level numbers aren't as good as they were last season, but he's actually hitting the ball even better, with expected stats that suggest he's actually been a bit unlucky. Perez does appear to have taken a step forward over the past two seasons, though his OPS after the All-Star break for his career is .042 lower than it is before, maybe because his massive workloads lead to some fatigue-related slowdowns. If there's risk here, that's where it comes from.

Pete Alonso - Chance of a letdown: 35%

Honestly, this might be a bit too high, because I think Alonso has probably underperformed so far this season. He has his lowest strikeout rate ever and has done it without sacrificing anything in quality of contact. His expected stats back that up, suggesting he's hit more like a .263 hitter with a .520 slugging percentage. In all likelihood, Alonso is probably going to be even better after the Derby.

Trey Mancini - Chance of a letdown: 35%

Mancini's comeback from cancer has been one of the best stories in the league so far, and there is good reason to think he can be even better in the second half. He's not hitting the ball quite as hard as he did in 2019, but his barrel rate is up from 9.9% to 12.9%, while his expected stats suggest he should have earned something like a .285 average with a slugging percentage .050 higher than his .460 mark. There's still a pretty good chance Mancini ends up with 30 homers and 100 RBI this season, and he's a buy for the second half in my eyes.

Trevor Story - Chance of a letdown: 5%

If this is too low, it's only because there might be a higher than 5% chance of the Rockies trading Story. There hasn't been much in the way of rumors either way, but he will be a free agent this offseason and the Rockies don't have much to play for in 2021, so it would make sense for them to see what they can get. Having said that, even if he does get traded, I think Story would be able to manage better than a .249/.323/.442 line in the second half.

Juan Soto - Chance of a letdown: 1%

You probably already missed your buy-low window on Soto, who is hitting .296/.418/.504 with 30-homer, 17-steal, 129-run, 109-RBI pace since the start of June. His underlying numbers have been fine all season, and I think he'll be even better than that .922 OPS the rest of the way. Soto is still a top-five player for me, ahead of Guerrero even, and I would still be trying to buy him if anyone values him as less than that.