I have been a fairly vocal skeptic about Cesar Hernandez and his improvement over the last year. It’s time I eat crow publicly. I thought César’s run of good outcomes would halt once pitchers adjusted back to him. Now, they’ve made adjustments and he’s still raking. Having looked at the underlying changes in his peripherals, I’m convinced he can continue to be an above average to borderline all-star second baseman. [Picks up fork and knife, cuts piece crow, puts in mouth.] So, while I’m chewing, I’ll try to say how César managed to transform from a placeholder 2nd baseman into a potential cornerstone of the future.
Over at Fangraphs, Dave Cameron recently diagnosed part of César’s turnaround. After being benched in Minnesota last season, César started doing three things that correlate highly with improved power and batting average on balls in play. First, he started pulling the ball more. Second, he generally has hit the ball harder, which often happens when a hitter pulls more baseballs. Third, he has hit the ball harder to the opposite field. Taken together, these improvements make it unsurprising that he has gone from a bottom-of-the-order slap hitter to a top-of-the-order on-base machine with sneaky power. But how did he manage that transition? What did he do to become not only more of a pull hitter but also a hitter who hits the ball almost as hard as Maikel Franco?
To answer that question we have to look at his approach, what pitches he’s been swinging at and where in the strike zone. To be a good hitter, you have to know your strengths and your weaknesses, and take advantage of opportunities that play to your strengths. Because pitchers make the first move, hitters are always in an initially passive strategic position. That’s why commentators like Ben Davis often quip, “Take what the pitcher gives you.” But to take the good from the pitcher and not the bad is a difficult task. Looking at a César’s approach should give us an idea of how he’s managed to play at-bats to his strengths and away from his weaknesses.
What we find, when we look, is that César has focussed his swings more on the middle of the zone and down. He’s eschewing pitches up more, especially those that are up and middle to away. But that’s not all. The improvements he’s made cannot be explained by selecting where in the zone to swing. He’s making better contact even in parts of the zone where he’s swinging less. So, he must be selecting more hittable pitches than he was before.
The story of these adjustments starts in Minnesota, June 21st, 2016. The Phillies were mired in a long losing streak that finally made us feel the reality of that team. It wasn’t good. César in particular was struggling at the time, hitting balls in the air, not very far, into opponents’ gloves. Pete Mackanin and Steve Henderson decided to sit him for the Twins series so that he could fix his uppercut and hitting more balls on the ground. (If Tom McCarthy’s version of the story is to be believed, Mackanin and Henderson did not tell César that he was sitting or why; he learned he was sitting by reading the lineup card and the reason from Andres Blanco, his replacement in the lineup. Mackanin tells a different story.) In the last game of the series, the Phillies finally ended their 9-game losing streak, and César returned to the lineup the next game. Before that point, since becoming a regular in the lineup, César had produced runs at a rate 16% lower than the average hitter (an 84 wRC+). Or to put that another way, he’d been significantly worse than the league average shortstop and slightly worse than the league average catcher, both positions where offense is often sacrificed for defense. After that point, César has produced runs at a rate 39% higher than the average hitter (a 136 wRC+). Or, far better than a league average DH. That’s comparable to the likes of Robinson Cano, Matt Carpenter, and Brian Dozier in 2016.
Here's the thing: César did not fix his uppercut and has barely reduced his fly ball rate. When I watch his swing closely I cannot discern a difference between now and pre-benching. And the reduction in his fly ball rate comes out to 2-4 fewer fly balls per season. It is safe to say that César improved without doing what Mackanin or Henderson prescribed.
Instead, César bucked the traditional advice given to speedy, short, slightly built middle infielders. Rather than try to spray the ball around the infield and leg out hits or hope to shoot the ball past rangy fielders, he aimed to hit the ball harder. There are two ways to accomplish that. First, pull the ball more. Second, find pitches that you are more likely to barrel up. We’ve already seen that César implemented the former tactic. But he also implemented the latter tactic, as we can see from the following zone profiles.
First, take a look at where César used to swing and where he swings now. He’s a switch hitter; so, we have to separate his at-bats against righties from those against lefties.
In general, you will see a couple of key changes. He has refocussed his swings on parts of the zone where he can get the sweet spot of the bat on the ball and square it up more easily (or, in the new-fangled parlance, optimize exit velocity and launch angle). For instance, he has brought his swings lower in the zone. Those pitches at the top of the zone were probably hard for him to get on top of and drive. Most likely, when he put those swings in play, they were turning into weak fly balls or pop-ups. By diminishing those swings he doesn’t necessary hit fewer fly balls, but he gives himself a chance to hit fewer fly balls that turn into outs.
César has also developed a new preference for low pitches on either side of the plate but not in the middle. I do not have a firm hypothesis on what benefit he derives from this adjustment, and maybe he doesn’t derive one at all. But one thought I had is that the low pitches inside provide some easy power, like his opening day home run, while the ones away are easier to drive to the opposite field, where he has also seen an uptick in exit velocity.
An interesting difference between his left-handed and right-handed approaches appears in how he treats the middle-in pitch. As a lefty, he has swung at more of those pitches by rate than he did before the benching. But as a righty he is avoiding them more than he used to. Given how infrequently César bats righty, it is possible this is just noise. But if not, it indicates a significant difference in his swing. He’s always been a better hitter from the right side, and his improvement from that side is even more pronounced. So, perhaps he still has room to improve on his left-side, if he swings at fewer pitches close to his hands and more of them further away.
As I said at the outset, these adjustments help explain César’s turnaround, but they cannot be the whole story. He is not just swinging at pitches that end up in parts of the zone that are better for him. His results throughout the whole zone have improved. Even where his batting average has decreased his power has increased. So, César must also be better at selecting which pitches to swing at. He must have become more selective. We have some evidence for this simply from his overall swing rate which has gone from 46% in 2015 to 44% in 2016 to 42% in the young 2017 season. His new patience is also reflected in his improved walk rate in the second half of 2016 (although, so far, that has not translated to 2017).
His new selectivity is also evidenced by these two charts.
In it we see that he has basically continued to swing at fastballs at the same rate. But he has reduced how much he swings at offspeed and breaking pitches (despite an uptick in swings at curveballs specifically). Based on that it seems César has either become better at recognizing breaking and offspeed pitches or better deployed his skill for recognizing them and selecting which to go after. Regardless of that, if he is putting a higher percentage of fastballs in play than he was previously then that would help explain his improved results because fastballs are just easier to hit. Moreover, it is possible—though hard to find evidence for—that he is swinging at more breaking and offspeed pitches that are hittable rather than the sort that draw whiffs and weak contact.
So, César’s adjustments—to the extent I can gleam them—were to select better where in the zone to swing and to hit more fastballs. This has allowed him to both pull more balls and hit them harder to all fields. The result is that, even though he still hits basically the same amount of fly balls, no one cares because those fly balls turn into hits, especially of the extra-base variety.
There is a crucial final question to ask. Have pitchers adjusted back to him yet? The evidence is ambiguous. His distribution of pitches in the zone has not changed much and pitchers didn’t change the mix of fastballs and breaking/offspeed pitches in 2016. But in the beginning of 2017 he is seeing a touch fewer fastballs and more offspeed pitches in particular. They are also pounding the zone against him in a way they had not before. Perhaps this is the start of a trend or perhaps it is the result of facing Max Scherzer, Noah Syndergaard, et al, ad nauseam. Whatever the case, he’s still been very successful, which bodes well for his future.