It Might Be Time to Adjust to Anthony Rendon

Pitch-pattern data can be interesting when you’re trying to spot trends or adjustments for scouting reports. Changes in pitch patterns can sometimes be revealing. Just the other day, we looked at Miguel Cabrera, and beginning in last year’s playoffs, pitchers started to challenge him with more fastballs over the plate. That trend continued into this April, as opposing teams picked up on the fact Cabrera wasn’t 100% after offseason surgery. With Cabrera not swinging like himself, pitchers often tried to blow him away. Now Cabrera’s getting back to normal, so pitchers, one figures, should soon return to their normal. Not that it’ll do them much good.

Pitch-pattern data can also be interesting and revealing when it doesn’t change. Wilin Rosario doesn’t see many fastballs, or strikes, or fastballs for strikes. What’s revealed is how people think of Wilin Rosario and his eye. The way Rosario gets pitched is perfectly justifiable, and this is an example of baseball finding its equilibrium. Yet there’s something curious I’ve noticed about Anthony Rendon. His name has come up when I’ve been researching other things.

Wednesday night. It’s the first inning, and Rendon’s facing Brett Oberholtzer. The first pitch is a fastball in the zone. The fourth pitch — a 1-and-2 pitch — is a fastball in the zone. The sixth pitch is a fastball in the zone that gets called a ball. The seventh pitch is a fastball in the zone, and Rendon hits it for a double.

Rendon singles on a curve in the third. He bats again in the fourth, and with the count 1-and-2, he gets another fastball in the zone. Rendon hits it for a double.

The second double lifted Rendon’s average to .313, his slugging to .518 and his wRC+ to 142. Though it’s been only a month, Rendon has hinted at a big season, which wouldn’t exactly come as a shock given his top-prospect background. He was a league-average hitter a year ago, and, a year wiser, Rendon seems primed to take a step or two forward. He’s one of the guys the Washington Nationals will be counting on in the temporary absence of Bryce Harper.

What’s a little odd isn’t that Rendon is hitting. Rendon was always supposed to hit. What’s a little odd is what Rendon’s been seeing. It would seem it’s high time for opposing pitchers to make an adjustment with Rendon in the box.

Since the start of last season, a third of all pitches to Rendon have been fastballs inside the PITCHf/x strike zone. Out of all big-league hitters who’ve seen at least 1,000 pitches, Rendon’s rate ranks third-highest. Just this year, 35% of all pitches to Rendon have been fastballs inside the PITCHf/x strike zone, and, again, that ranks him third-highest. On its own, that might not mean much to you, but, consider the company.

I took the top 10 in in-zone fastball rate for 2008, 2009, 2010, 2011, 2012 and 2013-2014. This left me with a pool of 60 player-seasons. Those players have averaged an .082 ISO. Rendon is approaching a .150 ISO. The list is populated by names like Marco Scutaro, Jeff Keppinger and Jamey Carroll. Guys who mostly don’t pose any sort of power threat. To those players, it makes sense to be more aggressive with your fastball. With Rendon in the box, it makes less sense, because while Rendon isn’t Harper, he’s perfectly capable of punishing the baseball.

We can go at this a similar but different way: Since the start of last season, 342 players have batted at least 250 times. Out of that group, 29 players have seen a fastball rate at least a standard deviation above the mean, and a zone rate at least a standard deviation above the mean. That group has averaged an .085 ISO. Rendon has the highest ISO of all 29. His fastball rate in 2014 hasn’t gone down, and his zone rate in 2014 has gone up.

Rendon has been pitched as if he doesn’t have power. He’s been pitched as if pitchers aren’t very afraid of him. And if his numbers now are any indication, it’s time to change things up, because this approach isn’t getting the job done. As far as I can tell, there’s been a sense Rendon has a vulnerability to inside heat. From last August:

One key to Rendon’s recent surge: He’s recognized that opposing pitchers were starting to bust him inside with fastballs, trying to exploit the hole in his swing. By getting the head of his bat through the strike zone quicker, Rendon has been able to make better contact on those pitches, producing better results.

In his brief career, according to Brooks Baseball, Rendon has made contact with better than 90% of inside fastballs. When he’s put those pitches in play, he’s hit .320. Not every inside fastball is created alike, though, and there’s a difference between 88 mph in and 98 mph in, but everyone struggles with 98 in. If Rendon has a vulnerability there, his numbers aren’t showing it. Pitchers are pitching him aggressively, Rendon is hitting them aggressively, and pitchers don’t like to get hit for very long.

Rendon, from the bottom of the same linked article:

“I just think it’s pretty funny how that can change within a game,” he said. “From your first at bat, to see how you are, to come back and attack you a different way in your second at bat, just to see how you were standing in the box. They pay attention to every detail. They try to use everything they can.”

I’ll concede I’m not a professional swing analyst. I can’t look at a guy’s hack and determine where he’s going to struggle and where he’s going to excel. I can’t give you a better Rendon report than an actual major-league front office could. But it’s funny now to see Rendon crediting pitchers for quick adjustments, when it seems like another adjustment is overdue. In 2014, pitchers have pitched to Rendon like they did in 2013. In 2014, Rendon has done more damage. And in 2013, he was by no means a problem. It seems like it’s time to pitch to Anthony Rendon like the good hitter he is, and probably already was.