How Good Has Jeremy Pena Been?
He was hot early and has cooled off lately. But overall, Pena has hit his offensive projections and has played Gold Glove level defense at shortstop.
It began with a joyous scream from his mother. While Heidy Watney of Apple+ was interviewing Geronimo Pena, Cecilia Pena let out a huge scream that burst through the audio of the broadcast, as her son Jeremy hit his first major league home run.
Geronimo then spoke for himself, his wife Cecilia, and all Astros fans “Happy, happy, happy now.”
And thus, the love affair between Astros fans and Jeremy Pena began.
It grew when Pena hit a two-run walk-off home run on April 24 to defeat the Blue Jays in extra innings.
And the peak clearly was when Pena’s appeared in the ultimate status symbol of an Astros star—and HEB commercial.
For the first two months of the season, Jeremy Pena was a sensation. He made his mother happy, he made me happy on my birthday, and he made us all laugh when he said “Salsa Night.”
And he seemed to be on his way to fulfilling Jose Altuve’s pre-season prediction that Pena “was going to be a superstar.” Over the first two months of the season, Pena slashed .281/.329/.490 for an OPS of .820. His 1.9 fWAR was 19th best among major league hitters for the first two months and tops on the Astros.
Since then, Pena has been much closer to an average major league player than a superstar. Since June 1st, Pena’s slash line has declined to .281/.263/.373. His 0.8 fWAR is 148th among major league hitters in that time period.
And this leads to the question. Which is the real Jeremy Pena? The All-Star level player that we saw in the first two months of the season? Or the league average player we have seen since then. I explore this question today.
A Defensive Star
The carrying tool for Pena is his defense. Reports from prospects watchers described Pena as “a plus defender,” a “plus plus defender” and “possibly a 70” as a fielder on the 20 to 80 scale used by scouts.
Pena has met every bit of those high expectations as a defender. The chart below shows Pena’s defensive numbers from four different advanced metrics. And in three of the four, they show that Pena is a top tier defensive shortstop this season. He’s 7th in MLB in Fielding Runs Above Average, 6th in Outs Above Average, and 2nd in Defensive Runs Saved.
A deeper dive into the fielding numbers show where Pena is strong as a defender. Baseball Info Solutions measures some specific components of defense. The estimate that Pena has saved 9 runs via his range, which is 3rd among all major league shortstops. They also estimate that he has saved two runs with his ability to turn the double play. That’s tops among all shortstops. The numbers from Baseball Savant show that Pena is particularly effective going to his right. He has 5 Outs Above Average when he moves that direction, 4th best among all major league shortstops.
In fact, many of the shortstops ahead of Pena on these lists are in the National League, with the notable exception of Andrew Velasquez of the Angels. Based on that field, Pena is a strong candidate to win the American League Gold Glove at shortstop in his rookie season.
Pena’s high level of defense provides a floor to his play. Even when his offense has slumped as it has over the last two months of the season, his defense makes him a contributing player. It’s the foundation of his value for the Astros and should continue into future seasons.
How Good is Pena’s Bat?
While Pena’s defense has remained strong all season, his bat has fluctuated across the season. The chart below shows Pena’s OPS by month. It went up from April to May, but declined to just below league average in June and has gone down further since, reaching an especially low .510 here in the month of August.
What has gone wrong with Pena’s swing? A look at the numbers shows that Pena has two big issues that are hurting him at the plate.
First, Pena is hitting particularly poorly when he is behind in the count. In those situations, Pena has a slash line of .158/.170/.211 for an OPS of .381. Of course, all hitters do worse when behind in the count, but the major league average OPS this season for hitters behind in the count is .514. Pena is worse.
Pena is very good when he is ahead of the count (a 1.005 OPS, compared to an MLB average of .953). And he is much better than the average major league hitter when the count if even—his .822 OPS is 38% better than the MLB average of .691.
So Pena is a better hitter than league average when even or ahead in the count, but when behind in the count, he’s much worse.
Pena’s second big problem is trying to hit pitches that bend, are slow (or both). Baseball Savant credits Pena with a weighted On Base Average of .365 against fastballs. His xwOBA is even better; it’s .400. But Pena is worse against breaking balls, with a wOBA of .290 and a xwOBA of .249. And he’s even worse against offspeed pitchers, with a wOBA of .146.
Obviously, these are related problems. Pitchers are more likely to throw fastballs when they fall behind in the count, and Pena loves to hunt them and hit them with authority. When the pitcher gets ahead of the hitter, he is more likely to throw a breaking pitch or a changeup and try to get the batter to chase a pitch out of the strike zone.
Pena’s Swing Decisions
Pena’s vulnerability to slower pitches when he’s behind in the count reflects the fact that he likes to swing the bat and that his batting eye is not an asset at the plate.
Pena swings at 54.3% of the pitches he sees, which 23rd most among qualified MLB hitters. He swings more at pitches inside strike zone (75.0% of the time; compared to an MLB average of 66.9%). He also swings more at pitches outside of the strike zone, chasing 35.9% of the pitches he sees that are out of the zone.
These swing decisions lead to fewer walks—Pena’s walk percentage is 8th percentile in the majors, and more swings and misses—Pena’s whiff rate is 29.7%, 5 percentage points higher than the MLB average.
Despite the extremes in Pena’s swing, chase, and whiff rates, Pena’s strikeout rate is at the 36th percentile, below the MLB average but not in an extreme way. How does he manage this? One way is by swinging at the first pitch of an at bat. The average major league goes after the first pitch 29.4% of the time. Pena does it on 46.1% of his at bats. He’s almost as likely to swing at the first pitch as he is to let it go.
For Pena, this is a good decision. In the 64 plate appearances this season in which he has hit the first pitch into fair territory, the results are excellent. He is batting .417 with 7 home runs and an .850 slugging percentage on the first pitch. The average hitter is good when they hit the first pitch, with an OPS of .904. Pena’s is much better, with an OPS of 1.272 against the first pitch.
And when Pena gets his pitch, he can do something with it. Pena is at the 72nd percentile among major leaguers in barrel rate.1 He has a max exit velocity at the 70th percentile. At the plate, his best tool is his power, which is impressive, especially for a middle infielder.
Pena’s free swinging ways are not a surprise. His walk rate declined as he advanced through the minor leagues and his projections entering this season anticipated that he would have a walk rate well below league average and strikeout around one-quarter of the time. Some hitters have good strike zone judgment and some do not. Pena does not, but his adjustment to hit more first pitches and hunt fastballs seems to be an effective adaptation to his skillset.
Why is Pena Slumping?
Pena may be an aggressive hitter, but he was an aggressive hitter in April and May when he was hitting better. Are pitchers adjusting to him and getting to swing and miss more?
The answer to that turns out to be no. The graph below shows some of Pena’s plate discipline numbers over the course of the season. You can see that Pena’s contact rate has been increasing over the last 6 weeks, as his slump has progressed. And as contact has increased, his share of swinging strikes (O-Swing%) has decreased. His chase rate has fluctuated up and down, but not in wild swings.
Overall, it does not look like Pena’s slump is being caused by pitchers adjusting to him and getting him to chase more pitches than he did earlier in the season.
No, it appears that Pena’s slump is caused by more mundane reason—BABIP luck and regression to the mean. When Pena was going good in May, he had a batting average on balls in play of .397. Analytical studies find than when a player’s BABIP is well above the major league BABIP of .291, it is likely to fall in the future. There seems to be little skill to avoiding the gloves of major leaguers; it’s most random variation working in your favor. And that seems to be the case for Pena, who had a BABIP of .235 in July and .268 so far in August. Balls that were falling in during the month of May are finding gloves in July and August.
The good news is that the low BABIPs that Pena has in July and August are as likely to last as the high BABIP that he had in May. His BABIP, and thus his batting average, should start rising pretty soon.
It will, thus, regress to the mean. Most things do. When a player is on a hot streak, it is not likely to last forever, and his numbers will soon return to what is a normal level. The same is true when a player is on a cold streak.
Pena was hot in April and May, but those numbers do not seem to represent his true ability as a major league baseball player. Instead, they reflect a hot streak he was on at the time. Pena seems to be on something of a cold streak right now and his numbers will return to average.
What is Pena’s True Level of Play at the Plate?
So what is average for Pena? At the beginning of the season, the ZiPS projection system thought that he would have a slash line of .253/.304/.424. Today, it projects for the rest of the season that Pena will have a slash line of .253/.300/.424. It is basically the same.
And it’s basically the same as Pena’s slash line for this season, which is .251/.292/.424. Heck, all three measures have the exact same projected slugging percentage for Pena.
Pena has had big highs this season, both on the field and in providing laughs in commercials and screams from his mother. He has proven to be a quality big league regular.
His high quality defense gives a high floor on his abilities as a major league player, and the team—which had one of the best defenses in the majors last year when the shortstop was Platinum Glove winner Carlos Correa—has not missed a beat defensively.
But his big offensive numbers in the early part of the season appear to be a hot streak. He is not that good of a hitter and is not really among the 20 best position players in baseball.
Instead, he is most likely the player that he has averaged out to be this season—a high quality major league regular. He’s not as good as he showed in the first two months and not as mediocre as he has shown in the last two.
Overall, he has posted 2.6 fWAR this season. That is better than the 1.5 to 2.0 fWAR he was projected for, which indicates that Pena’s season is a success for the Astros. And that 2.6 fWAR ranks 83rd among all major leaguers this season. Considering that there are 270 regular lineup spots and 150 starting rotation spots in the majors, that’s a demonstration of Pena’s value to the Astros in this, his rookie season.
In March, I wrote that “there are lots of reasons to think that Pena will become a quality major league shortstop and a contributor to the 2022 Astros…I think he’ll be quality defender whose offensive upgrades in the minors could make him an average major leaguer this season.”
I’ve gotten some things wrong in my analysis of the Astros, but that one was spot on. Jeremy Pena is helping this team and there is good reason to believe he’ll pull out of his current slump soon, even if he will not necessarily return to the highs of his May performance.
While there is a technical definition of a barrel, the colloquial combination works better—it is the perfect combination of exit velocity and launch angle. When a batter barrels the ball, it goes far and usually is a hit, often a home run.