Mountcastle Improvements

On Monday night, we learned that Ryan Mountcastle finished sixth in voting for the American League Rookie of the Year. This outcome was met with some frustration from Orioles fans, who believed a 33-homer season deserved more recognition than a sixth place finish.

And yet, I am not here to argue about Mountcastle’s finish in the race. However, it does seem like now would be a good time to highlight some things Mountcastle can improve on entering 2022.

Let’s begin with month-to-month consistency.

Back in April, Ryan Mountcastle was ice cold, finishing the month with an alarming slashline of .198/.229/.286. It’s normal to expect rookies to go through bumpy stretches, but a full month with a batting average below the Mendoza line for a highly-touted hitting prospect seemed like an ominous start to the season. Once Mountcastle put April behind him, he slashed a much stronger .266/.324/.528 and hit 32 of his 33 homers in the remaining months.

However, a month-by-month examination reveals that while Mountcastle never had a month as bad as April, he still spent May through October going through pretty notable up-and-downs.

You could get whiplash just by looking at his July and August back-to-back. I think the best way to highlight the wild disparity in quality over those two months is his August on-base percentage was higher than his July slugging percentage. When you combine July and August together you still get a very strong OPS of .913, but it’s also reasonable to wish that two-month stretch of productivity could come with a little more consistency.

It also helps to contextualize Mountcastle’s season-long .796 OPS with other hitters who finished the year with a similar figure.

Jake Cronenworth of the San Diego Padres finished with an OPS close to .796 but did so without an especially hot or cold month. His worst month failed to see his OPS dip below .700, while his best month didn’t see him clear 1.000 either. Neither of these were true for Mountcastle. When looking at the monthly numbers from these four hitters, only once did someone’s OPS fall below .600. Similarly, no one had a month with an OPS of 1.000 or higher.

It’d be great if Mountcastle continued to provide months with an OPS over 1.000, but dipping under .700 twice and almost doing it a third time to end the season sure looks like someone struggling with consistency in his first full season. Everyone has cold streaks, but for Mountcastle to reach his full potential as a hitter, avoiding months with an OPS under .700 should be something to aim for.

In addition to improving month-to-month consistency, Mountcastle would also benefit from walking more and striking out less. Of course, you can say that about virtually any player, but Mountcastle’s Baseball Savant page says he was in the 14th percentile for strikeout rate and the 25th percentile for walk rate in 2021, meaning he was noticeably below average in both categories.

If we’re looking for one culprit to explain how Mountcastle can increase walks and decrease strikeouts, we can look at sliders outside the zone.

According to Baseball Savant, Mountcastle swung and missed at a slider outside the zone 75 times this year, which ranked in the top ten across all hitters. The top ten also includes excellent hitters like Fernando Tatis Jr. and Salvador Perez, but either way it’s a clear weakness for Mountcastle to regularly chase that pitch outside the zone.

Out of 126 batters who saw at least 2000 pitches this year, Mountcastle ranked 26th in slider percentage, so there was a clear focus from pitchers on having him see that pitch frequently. To put that in perspective, Mountcastle’s percentage of fastballs seen was 90th out of the 126 hitters.

While sliders are especially worth highlighting when it comes to Mountcastle, he just wasn’t seeing many pitches in the strike zone in any capacity.

The Baseball Savant data says that 55.2 percent of his pitches seen were outside of the zone, which ranks seventh in baseball. Unsurprisingly, Mountcastle saw all those pitches outside the zone because he kept swinging at them. Data from Fangraphs says that Mountcastle swung at 41.5 percent of the pitches he saw outside of the zone, which ranked sixth on their leaderboard of 132 qualified hitters.

Mountcastle was still able to provide solid production with his free-swinging approach but you don’t exactly have to be Ted Williams to know that a pretty easy way to increase your walks and reduce strikeouts is to avoid chasing pitches.

Hitting 33 homers with a .796 OPS was one of the best offensive seasons from a rookie in baseball this year, but there’s no reason for that to be Mountcastle’s ceiling. Better monthly consistency and improved plate discipline would go a long way towards a successful career for a cornerstone of Baltimore’s future.