Trying to Understand Cesar Hernandez

This weekend Cesar Hernandez hit two home runs. Two is such a small number in the context of baseball, and most small events like this could be explained as small sample size noise. However, these home runs brought Hernandez to 3 in 12 games. This is Hernandez’s 5th major league season, and in the previous 4 he hit 8 home runs total. The spike is noticeable in the ongoing confusion that is Cesar Hernandez.

The introduction of StatCast has brought a larger voice to the concept that hitting the ball in the air is better than hitting the ball on the ground. This is not a new idea to anyone who has studied basic mechanics and specifically ballistics. The 2016 data bears this out too.

Batted Ball Type AVG ISO
Ground Ball .239 .019
Fly Ball .241 .474
Line Drive .689 .210

So how does this tie back to Cesar Hernandez? Here is Hernandez’s batted ball data in his time in the majors:

Now this is only part of the story. Making an adjustment is not no consequence change. To get the ball in the air, Hernandez had to change not just the angle of his contact, but where on the field he was hitting the ball to.

Where you hit a baseball matters for a variety of reasons. Most hitters have more power to their pull side, but it makes them more susceptible to shifts. Hitting the baseball up the middle is going to be a hit more often because of fielder placement, but the batter is also aiming for the deepest part of the ballpark. Hits to the opposite field make it difficult to shift a hitter, but it takes a lot of raw power to hit a baseball the opposite way.  Here are is the average BABIP and ISO for batted ball direction.

Ball Location AVG ISO BABIP
Pull .340 .294 .288
Center .340 .164 .315
Opposite .317 .149 .298

So by pulling the baseball more, Hernandez is going to give up some batting average, but it allows him to tap into his raw power. It is unsurprising, then, that until his game opening home run on Sunday, all of Cesar’s career home runs had been pulled to right field. The Sunday home run was the first that he had pulled to left field while batting right handed. Pulling the baseball has not just led to more home runs for Cesar, he also has been able been able to hit for triples down the right field line and into the right center gap.

A big problem in projecting out Cesar Hernandez in the major leagues has been his walk rate. With the exception of his 2011 season, where the Phillies had to aggressively skip him over Lakewood due to 40 man status, Cesar has always had a good walk rate. There are two fairly obvious parts of a walk rate, the hitter and the pitcher. The hitter has to not swing at 4 balls outside the strike zone without striking out or putting the ball in play. The pitcher has two throw 4 balls outside of the strike zone before the at bat ends. Pitchers avoid the strike zone for a variety of reasons, but the one we care about for this purpose is that they are trying to avoid giving up extra base contact to the hitter. Against a player with little power, the worst case scenario is maybe a double into the gap. Against a better hitter like say Bryce Harper, the result is much more devastating. Cesar’s highest isolated power in the minors was .146, but more telling is that even with a power surge in 2016 and into this season, his career isolated power is .088. At the time of writing this, that was the 26th lowest among all active players with at least 1000 career plate appearances (298 qualified). There is a general correlation between power and walk rates, where the lower the power output is, the lower the walk rate (it also helps that elite players tend to hit for at least some amount of power). Here is how it worked out for the 2016 season.

Cesar and Brett Gardner are the outlier spike at around .100 ISO. This definitely places Cesar as an outlier, but he also is now at nearly 1,400 plate appearances of a 9.2% BB%, which is enough to put forth the claim that this is somewhat real. At very least, his increase in power output will help offset any regression that was in his previous skill set.

So that covers the offensive side of the Cesar mystery, and it is a story that is not entirely uncommon, as attitudes have changed on previous conventions due to the influx of easier to process stats and outside hitting coaches. He is just hitting for more power, because he has adjusted how and where he is hitting the ball to hit for more power.

As for the rest of what else fueled Cesar’s rise, it is certainly not his baserunning, which continues to be maddening. It is his glove, which has gone from a bit of a liability to a definitive plus. He does not have a strong arm, and he can be prone to mistakes, but he does use his speed well to cover a good amount of ground, and he is willing to take some risks on throws, relying on an accurate arm to limit damage.

It is still tough to see Cesar being a star level player, but he was a 3-4 win player last year, and much like Odubel Herrera’s transition from unsustainable to sustainable, the introduction of more power to his game could make Hernandez the Phillies’ second baseman of the future, and not just a bridge to the future.

Batted Ball Data From Fangraphs

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  1. Mike Fassano

    April 17, 2017 04:41 PM

    He’s on the juice.

    • Matt Winkelman

      April 17, 2017 04:51 PM

      If you want to use StatCast exit velocity as a proxy for strength (he is a bit bigger) since we don’t have much better.
      2016: 87.3 mph
      2017: 89.1 mph

    • Romus

      April 17, 2017 05:49 PM

      He did gain weight and muscle -mass over the winter in a Miami fitness center with other MLB players. He admitted that prior to spring training.
      And I seriously doubt he would chance taking anything that would jeopardize his future earnings. and career prior to his last arb.
      There are legal supplements approved by the league players can utilize….I still think something like whey, or whatever powders they sell in GNC stores are not considered PEDs.

      • Bob

        April 18, 2017 01:07 PM

        The first thing that I thought when it was reported that Hernandez gained 15 pounds of muscle is that he must be taking some kind of supplement. Whey alone will not allow that weight gain in such a short amount of time. IIRC, Hernandez played Venezuelan ball too, so he had even less time to put on that much mass. To put on that much mass and maintain it in such a short time, he probably had to use some type of PED, not necessarily a banned one. If he had gained just fat, I would believe he didn’t use anything. I take supplements and I never gained that much mass in such a short time. The supplements that allow you to gain that much mass are risky.

        It’s not like all PEDs are illegal. The FDA bans stuff each year that was previously legal. Chemists change one compound and the PED will keep the same bennies but not be banned. He could be taking something legal that will become banned in the future, but he’s probably taking something.

      • Romus

        April 18, 2017 04:50 PM

        Well, if he did some illegal stuff he will be joining Pirate Starling Marte on the 80-game suspension plan. I sure hope he was not foolish enough to do that sort of thing.

  2. Ecclesiastes 1:9

    April 17, 2017 04:58 PM

    Thank you, Matt for not turning this article into yet another trendy leg kick/uppercut/Josh Donaldson proves crusty old coaches were wrong all this time narrative that seems to be sweeping the country. Ted Williams, Lau/Hirniak & Japanese league players have been doing this stuff for decades, but you’d never know because the “new discovery” proving old guys wrong narrative is just so seductive.

    Everyone is hitting homers at a record pace this year so far. Waiting for bigger sample size, but I’d guess the ball might be juiced this year? Manfred does seems the type to do whatever he can to make the game more exciting to the masses & I certainly wouldn’t blame him. Cesar has also come into this season much more jacked from working out (or whatever) than before. He’s bigger and stronger.

    The problem with he’s pulling the ball more analysis is that those things are largely a function of where teams are pitching you, especially for lead off hitter/non-3 true outcome types. Unless he’s crowding the plate more this year, there is no way that Cesar is consciously trying to pull pitches that shouldn’t be pulled.

  3. boomerbubba

    April 18, 2017 02:27 AM

    Time to trade him now while he has value, for stud Joe Blanton, before the Phils decide to fine-tune his hitting game like they did with Ryan Howard after his break-out seasons. The Nats might turn down the trade.

  4. Mace chutney

    April 18, 2017 04:07 PM

    It is a shame that baseball has created a “guilty until proven otherwise” mentality among fans where a player suddenly improves his physique and power. I hope the power spike is real, but given the game’s recent history, who knows.

  5. James

    April 18, 2017 11:01 PM

    I’m confused by the second table. If the ball is hit up the middle, then it is by definition in play. What is the difference between AVG and BABIP in this table?

    • Shane

      April 20, 2017 09:57 AM

      BABIP = (H – HR)/(AB – K – HR + SF)

      AVG does not count Sacrifices (SF) where BABIP does.

      • Shane

        April 20, 2017 09:59 AM

        and BABIP does not count strikeouts (K).

      • Shanghairen

        April 21, 2017 06:00 AM

        How do you split K by what field the ball was hit towards?

      • Vern Fleshman

        April 22, 2017 02:11 PM

        If it doesn’t affect striking out, why track them for pitching. The strikeout is getting left behind in baseball. Hitters don’t really care about striking out and pitchers, catchers and pitching coaches, and we can’t forget the manager/head coach they care if you average 10K’s a game that is very important on how you play everything that day!

  6. Major Malfunction

    April 19, 2017 04:17 PM

    This might be the first article about Hernandez where the story line does not state the best move (and normally only logical move) is to get rid of him, bring up Crawford, and move Galvis to 2B.

    His first bad week and we’ll be hearing about that again. As long as he adjusts to the pitchers who are adjusting to him, he’s an above average 2B.

    And by the way, Crawford appears to be way over matched in AAA right now. 105/227/385. He’s 4 for 38 in 11 games with 13 Ks. He’s not coming up anytime soon with those numbers.

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