Mike Yastrzemski, for whatever he ends up being as a player, is one of the greatest examples of Farhan Zaidi’s successful roster churn. In 2019, the Baltimore Orioles traded Yaz to the San Francisco Giants for minor-league pitcher Tyler Herb. Three years later, Herb has not yet cracked the majors and is now on the Seattle Mariners—meaning the Giants essentially got Yaz for nothing.

In parts of three major league seasons with the Giants, Yaz has put up 7.1 fWAR in 300 games, batting .255/.336/.500 with a 121 wRC+. Those numbers are buoyed by his exceptional 2020 season, where he finished 8th in NL MVP voting after putting up a .297/.400/.568 slash in 54 games (remember, 60-game season) with a 159 wRC+.

But Yaz came down to earth a little in 2021, slashing just .224/.311/.457 for a 106 wRC+. He still put up 2.2 fWAR, but after seeing the potential of his bat across 60 games, it certainly felt like a little bit of a step back.

So what can we expect from Yaz in 2022? Let’s go through the reasons to be pessimistic and optimistic (because I like ending on a good note!)

Reasons to Be Pessimistic

Yastrzemski’s struggles in 2021 were attributable to a dreadful performance against lefties.

Against RHP, Yaz put up an excellent .242/.328/.520 slash, with a wRC+ of 125. The OBP is slightly down from his career highs, but still perfectly respectable; this wRC+ would have ranked fourth among major league CFs with at least 400 PAs, or 9th among major league RFs with at least 400 PAs (in 2021).

But against RHP, it’s like Yaz somehow forgot to hit: he put up a .170/.254/.259 slash with a wRC+ of just 46. This would have been the worst wRC+ of a 2021 RF, and the second-worst for a 2021 CF (with 400 PAs), “bested” only by Jackie Bradley Jr. and his 35 wRC+ (but JBJ is buoyed by exceptional CF defense, whereas Yaz is passable in CF as opposed to great).

Why is this a cause for concern? Well, extreme splits like that often portend greater issues. For some reason, Yastrzemski just isn’t seeing the ball out of a lefty’s hand. And that’s concerning, given the makeup of the NL West, which has exceptional starting LHP (Snell, Kershaw, Urias).*

*An earlier version of this article incorrectly listed Darvish and Musgrove as LHP.

Yastrzemski isn’t getting younger.

It tends to be held that baseball players peak at age 27, and then enter a decline. The best 10 years for a hitter tend to be between 23-32 and then decline thereafter; very rarely do players have their best seasons past 32. At 31 years old, turning 32 during this season, Yaz is on the wrong side of that aging curve. His decline doesn’t have to be as precipitous as the change from 2020 to 2021 was, but it’s a cause for concern.

Pitchers are getting better at exploiting hitters’ weaknesses, and maybe this is just an expected adjustment.

With the advent of scouting reports, pitchers now have more data than ever on how to attack hitter’s weaknesses (e.g. if there’s a part of the zone they’re more likely to chase in). If we look at Yaz’s heat map, we see a pattern emerge:

Yaz was significantly more likely to whiff (swing and miss) on pitches in the upper left corner of the zone than the MLB average, which is a weakness pitchers can exploit.

Reasons to be Optimistic

Even with his struggles, Yaz was still a top-35 OF (by fWAR) and top-20 RF.

Despite his struggle against the high-and-away fastball and against lefties, Yaz still put up 2.2 fWAR; a starter by any measure of the word. Overall, given his encouraging success against RHP, he had a wRC+ a tick above average (106), paired with Gold Glove-nominated defense and the ability to play all three OF positions, though he was used most in RF.

Yaz only had one truly “bad” month in 2021; all the rest were significantly above average.

Here are Yaz’s wRC+s by month:

• Mar/Apr: 102
• May: 118
• Jun: 121
• July: 112
• Aug: 63
• Sept/Oct: 123

One dismal month does not a career make, especially when the other months were well in line with his career averages. Across 30 days, Yaz might just have entered a cold streak; one that defined his 2021 season, but certainly doesn’t have to define his career. And he made up for it with a solid Sept/Oct.

He hasn’t seen a spike in K-rate; a lot of his struggles are probably due to a significantly lower BABIP, which reflects luck more than skill.

Yaz’s K-rate stayed consistent at 24.6%; his 2020 season he had a K-rate of 24.4%, so no great jump. The major difference is that his BABIP in 2020 was .370, whereas that fell to just .254 in 2021. The average BABIP is usually around .300, so that reflects how luck was in his favor in 2020 and against him in 2021. His true talent level likely lies somewhere between the two extremes, and some regression to the mean will be due this year, meaning that his stats might look much better before all’s said and done.

Overall Takeaway

There are both reasons to be concerned about Yaz and reasons to be hopeful. So far in spring training (with the caveat it’s spring training), he’s gone 3 for 11 with 3 BBs and 3 Ks, with a home run and a triple mixed in. That’ll do, Yaz. That’ll do.

What are your thoughts? Do you think Yaz’s 2022 will look more like his 2020 or 2021?