A few days ago, in the FanGraphs chat room, there was a little discussion about whether Statcast more favored run production or run prevention. I’m of the mind that having so much information works to the advantage of the pitchers and defenders, myself. I wrote about that a couple Hardball Times Annuals ago. But it’s by no means a settled matter. Someone during our conversation pointed out that, while Statcast is new to us, teams have had access to HITf/x for years, so they probably already had their ideas. Yet, perhaps Statcast makes everything easier. Perhaps more teams are just on board now than before. I don’t know. Many angles are interesting!

There’s something about Statcast that I think might be underappreciated. And it would be true about HITf/x, too, but Statcast is the thing that we get to see, so let’s roll with it. As a demonstration, I’m going to use Jose Abreu, of the White Sox. Abreu hasn’t been terrible, but he hasn’t quite been himself, not yet. Why is that? Could be any number of things, but it could have to do with how he’s been pitched. This is where Statcast can serve a purpose.

Hot and cold zones have existed as a concept for decades. You know the ones, where red means a hitter is more productive, and blue means a hitter is an easier out. Some hitters have hot zones down, over the plate. Some hitters prefer pitches up. Some hitters seem to be able to clobber everything. Some hitters are Jeff Mathis. Hot and cold zones are right at the heart of every scouting report. When catchers try to read hitters and swings, they’re mentally plotting a perceived hot/cold map.

Every hot/cold plot you’ve ever seen has been determined by outcomes. There was never any other way. And obviously, outcomes are tightly correlated to ability, so it’s not like they should’ve been totally misleading. But think about where we are with Statcast. Suddenly, we know how hard hitters hit the ball. Is there any truer measure of talent? Used to be, we had hot/cold plots based on singles and triples and outs. Now we can have them based on batted-ball speed. You can even look this stuff up on Baseball Savant in a matter of seconds. We have access to probably the best scouting reports ever. Or at least, to the material that would inform the best scouting reports ever.

Here’s a Baseball Savant plot, for Abreu, since the start of last season. This is for Abreu against fastballs only. The total sample numbers greater than 300.

Abreu bats right-handed. So, he’d be over to the left. What do you see? Based on this, Abreu does an outstanding job covering the outer third. He’s also been very good at hitting pitches over the middle hard. (You’d hope so.) There’s more of a vulnerability inside. This is true of most right-handed hitters, but it seems to be especially true for Abreu.

Forget the bins in the image above. Let’s simplify! Against fastballs over the inner third, or more inside, Abreu has put up an average batted-ball speed of 86.6 miles per hour. That ranks him in the 54th percentile. Against all other fastballs — so, fastballs over the middle third or away — he’s put up an average batted-ball speed of 97.4 miles per hour. That ranks him in the 96th percentile. Abreu has a difference here of about 11 ticks, whereas the league average is closer to six. So, it’s demonstrated: Jose Abreu isn’t so great at handling inside heat. Not relative to what he does against other fastballs.

When Abreu first came to the majors, there was talk that he could be vulnerable to heaters, so this isn’t a new idea. But now we could say it’s known, and we can talk with more precision. Abreu is actually quite good against many heaters. But he can be tied up. And now look at what else could be observed. Last year, against Abreu, 46% of fastballs were over the inner third, or more inside. That was one of the highest rates in the game! This year, Abreu is at 59%. That’s easily the highest rate in the game, among righties — second place trails by eight percentage points. Abreu’s rate was already extreme, and now it’s gone up another 13 points. Abreu isn’t actually seeing more fastballs overall, but the fastballs that he is seeing are less frequently out over the plate.

I keep using rolling-average plots. Here’s another one, for Abreu’s career. This shows inside-fastball rate in 20-game chunks. I don’t know why I chose 20 games, but that’s what I did.

Like with any plot, there are ups and downs, but right now we’re at the highest up. The Twins publicly acknowledged they like to work Abreu inside. The Yankees didn’t say anything publicly, but they might as well have. As an example, here’s Abreu against Aroldis Chapman the other day:

The final pitch of an at-bat that had already featured so many inside fastballs:

Back to the well, after Brian McCann read Abreu’s stance. You can’t exactly treat a Chapman at-bat as being representative of all at-bats, but this is just one example, and you’ve already seen the bigger-picture numbers. Teams seem to believe Abreu has a weakness in there, and they’ve attacked it. Teams have always attacked perceived weaknesses, but with Statcast, now this doesn’t have to just be an educated guess.

I don’t know if teams are going inside on Abreu because of the data. That might simply be a coincidence — I don’t talk to the pitchers and catchers. They’ve gone through phases similar to this before. Mostly I just think this is a useful demonstration. With the information we all have access to now, we can see more clearly than ever that Jose Abreu isn’t a great hitter when he gets an inside fastball. If you miss over the plate, he could destroy the pitch, but pitchers have moved those fastballs more inside, and Abreu hasn’t yet produced like himself. Statcast gives us the surest hot and cold zones. HITf/x probably did the same thing, but the whole league is increasingly analytical. Just having this information is wonderful. All the consequences? There are potentially innumerable consequences.