Diving In: Who is the real Cesar Hernandez?

When Cesar Hernandez was coming up through the Phillies system, I had hoped he’d end up being a player like Placido Polanco. Like Polly, whose career batting average sits just below .300 and whose on-base percentage is just above .340, Cesar was performing in the minors as a high-average infielder with no power to speak of. While power is favorable in every player who can muster it, that’s simply not the type of player Hernandez was ever going to be.

I still thought he could add value, though, if he followed the Polanco model of reaching base and playing good defense. Polanco was worth 2 or more fWAR in 11 of his 16 seasons; only once did he play more than 115 games and not reach 2 fWAR (the last year of his career).

Part of this value undoubtedly comes from defense, and Hernandez’s fielding has been worse than Polanco’s by both the eye test and advanced metrics. Polanco put up a negative ultimate zone rating three times in his career and a negative defensive runs saved only once, but Cesar has been in the negatives in both in three of his four seasons in the big leagues.

The other difference between the two is in strikeouts. Hernandez has gone down on strikes 19.6 percent of the time as a major leaguer, which is entirely too often for a player who doesn’t pose a power risk. He can’t do much damage in one swing of the bat, so he’ll have to accrue damage over the course of multiple at-bats, instead. This is something else Polanco excelled at: he struck out 6.8 percent of the time in his career, and his 91.9 percent contact rate is the sixth-highest in baseball among hitters with at least 300 plate appearances since the stat became available.

So my comp, as virtually all comps do, fell short. Hernandez’s first few seasons didn’t give a clear sense of what he would become or if he’d grow out of being a below-average hitter who made a lot of soft contact. His first 34 games, coming in 2013, included a promising .344 OBP but not much else: Ben Revere type power without the steals, uninspired defense, and below-average wOBA (.305) and wRC+ (91).

From there, it got worse. In 2014 he hit .237/.290/.281, which is a slash line usually reserved for journeymen, guys stuck between the minors and majors, and utility players who change teams every year because they can play any spot on the field. He struck out 26.4 percent of the time. 2015 was better – .272/.339/.348 – and his first season with a positive fWAR, but the average was still empty, the defense still not favored by defensive metrics, and some Phillies fans were open to giving his starting second base job to shortstop Freddy Galvis when J.P. Crawford would be called up, whenever that might be.

Then 2016 happened. Hernandez led the Phillies in fWAR (4.4), batting average (.294) and OBP (.371), and had a second-half wOBA of .364. His second-half OBP (.413) was sixth in baseball.

The biggest question arising out of those results is what caused the sudden improvement and, depending on the answer, whether or not the improvement is sustainable and Hernandez will continue to be a 4-win player.

Why was he so good in 2016?

The possibility exists that 2016 was a year of natural growth for Cesar that was forecast by his improvement in the season before. One might argue that his 2013 batting average was a fluke and that his improvement from 2015 into 2016 simply matches his improvement from 2014 into 2015, signifying the type of trend one might expect from a young player adjusting to the league. Every stat he improved in last season – average, OBP, slugging, wOBA, wRC+ – was also one he improved in 2015.

Hernandez’s early-2016 performance was unremarkable compared to his career totals. Through May, Cesar was hitting .256/.308/.321, which didn’t have anyone thinking of him as a breakout candidate.

In fact, the breakout happened suddenly. In June he hit .305; in July, .333. His June wOBA leaped to an above-average .330 and grew each month for the remainder of the season, reaching a peak  of .373 in the month of September (and two games in October). This provides an easy place to start looking for explanations to see if he changed anything in June and onward.

Unavoidably, Hernandez’s BABIP – batting average on balls in play – increased throughout the season as his batting average did. During his June-October hot streak, his BABIP was .382 but had been .339 for the rest of his career. Because BABIP inflation is often a sign of a batter getting lucky and having more balls in play turned into hits than before, despite not actually hitting the ball any better, the first step is in ruling out luck by finding some other explanation for his better results.

Batted-ball data is one way to do this. What follows is provided with the usual caveats of small sample sizes; batted-ball data does not always stabilize within the several-month span we’re looking at here …

During his hot streak, Hernandez hit 3 percent more line drives and 4 percent fewer fly balls than he had up to that point in his career. His hard-hit percentage rose by almost 5 percent, from 22.7 to 27.2. This sounds negligibly small, but baseball has always been a game where a lot can come out of the most seemingly tiny margins. For example, Hernandez put, by my calculation, 417 balls in play last season. 4 percent of that – the difference between his previous fly-ball percentage and his improved one – would be 17 balls in play.

Fly balls generally become outs – Cesar hit .181 on flies last season compared to .262 on grounders and .720 on line drives – so minimizing them was one of the factors that improved Hernandez’s batting average. Say, for example, that his hot-streak fly-ball rate had been sustained over the course of his entire season, and that he did hit 17 fewer fly balls. Even if they led to just five more hits than they would have been as fly balls, his 2016 average would jump from .294 to .303. This is all strictly hypothetical, back-of-the-napkin math, but it illustrates how small margins can add up and explain sizable statistical differences.

Hernandez decreased his fly-ball rate specifically against off-speed and breaking pitches. It’s also encouraging that he walked more starting in June – 12 percent of the time compared to the 8 percent he had averaged in his career to that point – and whiffed on breaking pitches less frequently, hopefully suggesting that his success comes from squaring those pitches up more. How he handles breaking pitches and change-ups will be something to watch for going forward, especially if he intends to cut down on strikeouts.

Unfortunately, the different approach turned mostly to ground balls instead of line drives. While that represents an improvement over flying out all the time, it suggests he’s still not barreling the ball up against a full arsenal of pitches. Given his lack of power and the fact that he did hit more line drives against fastballs than ever before last season, it’s possible that pitchers will make an adjustment and stop giving him anything straight to swing at. Even once he’s on base, Cesar tends to become a liability, so even the threat of walking him might not scare pitchers off approaching him with junk.

Looking ahead to 2017

All of this is to say that fans should be open to the possibility of some regression. His .363 BABIP was the eighth-highest in the baseball last year and will be difficult to sustain even if there is some explanation for it being higher.

There is also the fact, as I mentioned already, that batted ball outcomes are not set in stone within a few months. If he can’t sustain his increase in hard-hit balls and avoiding the flies, he’ll likely end up back where he was.

The goal for Cesar, ultimately, should be in striking out less and continuing to improve the quality of contact he makes when he does swing. In a word, he should be selective. Walking more in the second half of last year is an encouraging sign to this end, meaning he has a better understanding of what’s being thrown to him.

The success he achieved in 2016 is beyond what many expected from Cesar Hernandez after his first three seasons in the majors, so it’s difficult to expect him to improve even further. 2016 may have been Cesar Hernandez in peak form. As it is, that would make for a very fine player who could continue getting on base at the top of the order— something the Phillies desperately need if they intend to score more runs next year.