Buy High, Sell Low: Juan Soto, Casey Mize, Andrew Vaughn (2021 Fantasy Baseball)

One of the most powerful elements in predicting sports outcomes is the overreaction to past events. I write about it at the beginning of every new season, and then again when another opportunity presents itself.

The opportunity is currently presenting itself.

The All-Star break isn’t exactly the midway point of the season, but it serves as a de facto halftime. MLB teams and fantasy managers use the pause to reassess their situations. Those who misplace value on the first-half numbers or the ones we’ve witnessed over the past week may make a rash decision.

As always, this column seeks players who are gaining attention in one direction or another and are expected to continue along that path.

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Players to Buy High

Juan Soto (OF – WAS)
Don’t look now, but Juan Soto has just vaulted himself up the hitting leaderboard and erased his slow start to the year. This is why we often refer to baseball as a “marathon, not a sprint.”

Soto’s surge has been nothing short of jaw-dropping, but it’s not just the power he’s exhibited since the All-Star break (five home runs in five games). Soto’s hot streak is made even more impressive because he participated — and shined — in the Home Run Derby.

At first glance, this is troubling for Soto’s asking price. He put on a nationally-televised show and reminded everyone watching of how much talent lies in his bat. It’s hard to think any fantasy manager would sell at a discount after that performance, and the price has only risen since then due to Soto’s dominant week.

Still, I’m buying.

Soto was a potential top pick in fantasy drafts this year, and his first few months were only a disappointment because of the high bar he had to reach to justify the selection. Now, he’s soaring toward his initial perceived value, so we’re still buying on the way up.

Casey Mize (SP – DET)
While the focus of this column is on re-draft leagues, it will probably be important to remember Casey Mize’s 2021 campaign. He’s taken the first “next step” in his development, approaching 100 innings with a solid 3.44 ERA.

Mize is a repeat name in this article, as he appeared roughly two months ago as a “Buy High” candidate. It’s rewarding to see his value has held since that point, and I am still on the aggressive side of acquiring him.

I am also cautious when it comes to young arms, and we may be buying Mize for a different role than previously expected.

Mize has not allowed more than two earned runs in any of his last three starts, but he also hasn’t pitched past the fourth inning. That’s concerning since he will almost certainly be limited for the remainder of the year. After all, this is a key piece of the Tigers’ future rotation, if not their ace.

If we can stomach the fact that Mize may not go deep enough into games to record wins — something that was always a risk pitching for Detroit — then we can add him on a per-inning basis. That is where his stock may continue to rise.

Kwang Hyun Kim (SP – STL)
I’m kicking myself. During the preseason, I targeted Kwang Hyun Kim as a nice sleeper regularly drafted embarrassingly low. Unfortunately, in the weeks leading up to the start of the regular season, Kim started dealing with injuries. It muddied the outlook for 2021, and I opted to stay away.

This is why I’m kicking myself.

Through 16 starts, Kim is now pitching to a 2.87 ERA. He hasn’t allowed a single earned run in his last three starts, and his 19.7% soft-hit rate ranks 21st out of all starters with at least 70 innings pitched.

The one downside to Kim is his low strikeout rate (18.2%) is low. That, coupled with his dependence on inducing soft contact, has resulted in a few games in which opponents took advantage. Most of that damage happened earlier in the year, but Kim is now settled in and regularly delivering for fantasy managers. I’d pay a premium to be one of those managers.

Players to Sell Low

Andrew Vaughn (1B/OF – CHW)
If I’m going to be fair about kicking myself regarding Kim, I will also admit I kicked myself when missing out on Andrew Vaughn earlier this season. Unlike Kim, Vaughn has not made me regret the decision. He hasn’t been terrible, but he also isn’t providing enough to fantasy managers. As of this writing, Vaughn has a 0.0 Offensive WAR with a .243 batting average.

That’s not cutting it.

Vaughn won’t steal bases, he has shown moderate power, and he’s neither scoring nor driving in enough runs for an offense that ranks fourth in runs-per-game.

Vaughn is a gamble, and I’m not willing to take a chance on what he might do over the latter half of his longest professional season. Remember, he skipped both Double-A and Triple-A en route to the White Sox, and he’s already played more MLB games (80) than in the minors (55).

Ryan Mountcastle (1B/OF – BAL)
Ryan Mountcastle has been a roller coaster since the start of the season. His second appearance in this column is an indication that, for every peak, there is also a valley.

Tracking Mountcastle’s numbers over the year, it almost appeared as if he were turning a corner. The same “Sell Low” I placed on him was probably viewed as a “Buy Low” for others. And it worked for those who bought. Until it didn’t.

Mountcastle is now negative again in terms of Offensive WAR (-1.4), and his on-base percentage has fallen below .300. The home run potential will keep fantasy managers intrigued — he actually remains a solid option when playing DFS — but his inconsistency is hurting season-long fantasy teams. He also hasn’t gone deep in July and has just two extra-base hits (both doubles) this month.

For the second time this season, I’m moving on from Mountcastle and not looking back.

Griffin Canning (SP – LAA)
We’ve seen this from a relatively large number of players, and it supports the questions asked during the preseason. If a player’s performance spiked during the COVID-shortened 2020 season, could we trust these numbers going into 2021, or is the year an outlier?

For some players, 2020 was the start of a new trend.

For Griffin Canning, it was not.

Canning was average in 2019, but his underlying numbers showed he could have produced at a slightly higher level. He reached that level in 2020, but apparently over-corrected. The same numbers that suggested a positive regression now pointed in the negative direction. Canning, again, followed the gravity of regression and now sits at a pitiful 5.60 ERA.

During this three-year dance, Canning has maintained a consistent and solid strikeout rate. It sits right around one batter-per-inning and has hardly deviated from that mark, even in the minor leagues. However, his strikeout rate isn’t superior enough to overcome a high ERA and WHIP.

The Angels hoped Canning would answer their pitching woes, and fantasy managers were surely doing the same. He isn’t delivering for either.

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Mario Mergola is a featured writer at FantasyPros and BettingPros and the creator and content editor of Sporfolio. For more from Mario, check out his archive and follow him @MarioMergola.