2020 K% Risers: Buy, Sell, or Hold

Nicklaus Gaut analyzes differences in strikeout rates since last season using plate-discipline metrics and Statcast data to determine if fantasy baseball managers should buy, sell, or hold these players.

Heading into Thursday's action, most teams had played at least 15 games, officially passing the quarter-pole of the 2020 season and giving us a large group of players that have reached at least 60 plate appearances. This is an important milestone in terms of looking at strikeout rates, as the metric is one of the quickest to start to stabilize and 60 PA is around where we can start taking the data more seriously.

Today we'll look at the biggest strikeout increases among players who've reached 60 PA, as well as take a quick peek at some players who will cross the threshold soon. Will the strikeout rates today be guaranteed to be those of tomorrow? No, but they should serve as a pretty decent barometer for the remainder of the season. Or, at least tell us where a player is currently at in terms of his plate discipline.

I'll be taking a longer look at four players who were drafted in the top-100 but have greatly disappointed so far in 2020. We'll use plate-discipline metrics and StatCast data to try and figure out what's in store for the rest of the year and whether you should be trying to buy, sell, or hold your shares.

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Biggest Increases in Strikeout Rate

To be clear, in today's game, more strikeouts don't necessarily mean a worse fantasy return. It's not a direct correlation and sometimes more aggression can be good.  To illustrate this, I've also included the change between the player's wOBA in 2019 and 2020, along with their change in strikeout rate. Here are the biggest increases, ordered by total change.

Rafael Devers (3B, BOS)

2020: 33.8% K% (16.8-pt increase)

It is legitimately hard to find silver linings in Devers' metrics this season so why don't we get them out of the way first? He has a 10.5% Brl% that is slightly higher than his 9.0% Brl% in 2019 and his .414 xwoBACon isn't far off from last year's .429 mark. And that's about it.

After filling up the stat sheet every which way in 2019, Devers (and most of the Red Sox) has been a disaster this season, striking out like Joey Gallo but only hitting two home runs, while slashing .167/.231/.333. His x-stats aren't any better, with a .220 xBA and a .293 xwOBA, while his exit velocity is down almost 2 mph.

Digging further into his plate-discipline, there seem to be issues with Devers' strike recognition, both in his performance on pitches outside the zone and falling behind early too often. Devers went from a 61.1% F-Strike% in 2019 to a 75.4% F-Strike in 2020.

Let's get a little more granular and look the first pitch results in all of his 65 plate-appearances this season:

Remember that F-Strike% includes balls hit into play, as well as pitches that result in strikes. Stripping F-Strike% down to just the strikes, Devers has started 0-1 in 61.5% of his plate appearances in 2020, compared to only 48.2% in 2019. We all know that a 1-0 count is more advantageous for a batter than o-1 but how has Devers, in particular, performed in the different counts?

Putting counts aside, Devers has also struggled with his strike-recognition and overall plate discipline, going from a 12.1% SwStr% in 2019, to a 16.4% SwStr% in 2020. He's also been chasing a lot of cheese. Here are his numbers from 2019 and 2020, looking at totals swings and whiffs on only pitches outside the zone:

Devers is falling behind more and swinging at more bad pitches while connecting on fewer of them. His overall contact is down and so is his quality of contact. He's also on a team that has seemed to be mailing it in since game one. If I'm a Devers owner (and I am), I'm looking to move him the next time he has a big game. Something along the lines of, "See, fellow owner. I told you he's turning it around. Why don't you take advantage of me "selling-low" and get yourself a potential first-rounder for the rest of the season?"

It's times like these when I wish I played in a fantasy league with Jerry Dipoto.

Verdict: Sell

Marcus Semien (SS, OAK)

2020: 27.3% K% (13.6-point increase)

As more proof of 2020 being a bizarro universe, Semien is striking out at his greatest rate since his first 85 games after coming up with the White Sox in 2013-14. Semien has averaged a 19.3% K% in the five seasons since but has suddenly spiked after his breakout 2019, when he slashed .285/.369/.522 over 747 PA, with 33 HR and 10 SB.

Besides the near 14-point in strikeout rate, Semien has cut five points from his 11.6% BB% last year, while going from a .391 woBACon to a .297 mark so far this season. Taking a look at his plate discipline numbers, something is certainly up, whether it's related to a change in approach or in his pitch recognition:

He's swinging more overall but all of that increase is coming on pitches outside the zone, as his swings on pitches in the zone went down two points. He made much less contact overall, seeing near 7- and 13-point drops, on pitches in and out of the zone. Is this more aggressive approach a result of him trying too hard to replicate last season's power outburst?

Semien has raised his launch angle to 18.2 degrees from last season's 14.9 LA, dropping his groundball-rate five-points and raising his flyball-rate by four-points. Unfortunately,  his pop-up rate is at a career-high 12% and he only has three barrels on the season, with his 85.6 mph average EV representing a career-low as well, losing over 3 mph from last season.

If you're looking to move him now, it's likely you'll only get pennies, given his horrible start combined with many fantasy players going into 2020 believing that 2019 was a fluke. And I hate trading for pennies. With Devers, at least you can still get a pretty good price given the name value but Semien's going to be a tougher sell, especially given how deep shortstop is. But I'm much more confident that Semien turns it around from a fantasy value perspective.

For one thing, he eats PA's for breakfast and should have a pretty long leash on Oakland's leadoff spot. It might be a different story if Khris Davis wasn't such a disaster, as they could move Semien to sixth or seventh and bump everyone else up a spot. But with Davis so lost, batting Semien sixth would result in Mark Canha batting cleanup and Robbie Grossman at fifth. That's not likely ideal in Oakland's eyes. Hopefully, Semien remembers that he's Marcus Semien and doesn't actually need to hit at a 30-HR pace when he has legitimate big power bats coming behind him.

Verdict: Hold

Josh Bell (1B, PIT)

2020: 30.8% K% (11.6-point increase)

Trapped in doldrums of Pittsburgh's terribleness, Bell has fallen off of a disciplinary cliff, striking out nearly 31% of the time after averaging an 18.2% K% for the previous four years of his career. He also averaged a 12.1% BB% prior to this year, where he now sits at a paltry 4.6% BB%.

Watching his at-bats, Bell is often up there hacking, at least relative to his prior patience. His swings on pitches in the zone have stayed level but he's seen a seven-point jump on swings outside the zone, going from a 26.3% O-Swing% to a 33.6%, while his contact on outside pitches has dropped 16-points. But his contact is actually down across the board, dropping 11-points on pitches inside the zone and almost 14-points overall.

The batted-ball data also isn't very encouraging, as Bell is back to a 35.7% Pull% after having a career-high 42.5% pull-rate last season. And an unseemly 15.4% infield-fly rate certainly isn't helping matters. Pulling the ball less while popping up more makes not a recipe for success.

While I'm loathed to sell players off at rock-bottom prices, I'd happily move Bell if I could get a decent collection of parts to patch up my roster. Niko Goodrum + a high leverage reliever and streamable starter? Why not!

Verdict: Sell

Christian Yelich (OF, MIL)

2020: 31.8% K% (11.5% increase)

Talk about a cold open. Yelich is only slashing .175/.288/.456 through his first 66 PA, with four home runs and zero stolen bases. A .188 BABIP may point to better times ahead but his .237 xBA isn't exactly rosy considering he was supposed to be an elite contributor in batting average. There is some decent news, as his walk-rate has stayed steady and his swings on balls outside the zone have dropped by 10-points.

But Yelich is actually down in swings across the board, with his overall swings and swings in the zone dropping by nine- and seven-points. Combined with a nine-point drop in contact-rate and you wind up with a version of Yelich that is swinging less and making less contact when he does swing.

There are also some troublesome numbers in his batted-ball profile, with modern-day Yelich doing his best impression of Miami Marlins Yelich. After chopping swathes off his groundball-rate and posting a 42.8% GB% in 2019, Yelich is back up to a 55.6% GB% (his highest mark since 2017). Looking at Fangraphs, it appears that his flyball-rate has only dropped slightly, going from 35.9% FB% to a 33.3% FB%.  But when using data from Baseball Savant instead (which doesn't include pop-ups in FB%), Yelich has actually dropped almost nine-points, going from a 28.1% FB% to a 19.4% rate.

My opinion on Yelich changed over the course of the offseason, lowering after the Brewers lineup was crushed by free agency, with poor substitutions being swapped in for Yasmani Grandal and Mike Moustakas. But they raised back up post-pandemic, as I thought batting average would be overweighted in a 60-game season and that was a category I thought I could count on. Not so much.

The batting average has to bounce back, right? I mean, runs, RBI, and stolen bases I had my worries about but Yelich's average is supposed to be a lock, with a .300 AVG representing the floor. So, the optimist in me would be looking to trade for Yelich, hoping he goes on a 40-game burn, something he's proven more than capable of doing.

But only for the right deal. I'm not going to make insulting offers but I'm definitely getting a big discount if there's going to be a deal ("How can I give more? The season is a quarter finished", etc.). However, if there's a disgruntled Yelich owner - perhaps someone who wasn't a Yelich guy but begrudgingly took him third because he felt he "had" to? That's the owner I'm lowballing, throwing together a pu-pu platter of parts that I'll pitch as filling multiple needs.

Verdict: Buy

Almost Qualified

Our cutoff was 60 PA but there are 63 batters who didn't make the cut but still had more than 50 plate appearances heading into Thursday's games. We'll end by taking a quick look at the worst of the rest.

• It just goes to show you; never underestimate how much Gary Sanchez loves to strike out. We used to think that Sanchez's biggest fantasy hindrance was his inability to stay on the field. Now, staying on the field might be a worse option for his owners. Sanchez is slashing .104/.204/.250 with two home runs and a 28 wRC+, making Gary the snail a better option.
• Sooooo...We might need to talk about the Mitch Garver breakout. Because last time I checked, single digits on Baseball Savant weren't good.

• The epic Andrew Benintendi flameout...Now with all-new 33% K-rate and multiweek injury! Benintendi has a .103 AVG with zero home runs and just hit the IL with a rib injury and is expected to miss more than the minimum amount of time. I already can't wait to overly invest in dirt-cheap shares next season.
• If there's a guy to try and buy low on, it's Kyle Schwarber, who's seen a jump in his K-rate even though he's dropped from a 11.1% SwStr% in 2019 to a 9.8% this season. His plate-discipline metrics are also mostly the same across the board, with the only significant change being over an 18-point increase in contact on pitches outside the zone.  He has a .464 xwoBACon that's in the elite range and his 94.2 mph EV is in the top-3% of baseball and is about a one-mile bump up from last season.

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