Michael Brantley cringed a little when the term was mentioned. Thanks to advancements in technology, a new wave of statistics have started to gain momentum in what is becoming known as the Statcast Era.

One of the new metrics is launch angle. Brantley isn’t one of its disciples.

“I don’t believe in launch angle,” Brantley said on a recent morning. “When you say launch angle to me, it means nothing. It means getting the barrel to the baseball. That’s all I believe in. Launch angle is the byproduct of a good swing.”

This brings us to the curious case of Yandy Diaz. We’ll get more into what Brantley meant in a bit.

During his 15-game taste of the Major Leagues, Diaz’s offensive performance was far more unique than his .236/.295/.255 slash line would indicate. The rookie ranked near the top of baseball in hard-hit rate, but at the bottom in launch angle. Pitches were rocketing off Diaz’s bat, but were being pounded into the ground, especially the opposite way.

The question then becomes: How can Diaz correct this? Now back with Triple-A Columbus, is there something he can work on to get more lift on the ball? It’s easy to look at the -0.1 degree launch angle on his balls in play (lowest in the Majors among batters with at least 25 results) and think that a simple improvement in his angle would correct the issue.

The Indians actually have no plans of instructing Diaz to alter his swing. In his specific case, it goes back to what Brantley said. Diaz’s launch angle should improve naturally with better pitch selection and an improved understanding of when he should expect pitches that he can do more damage with to the pull side.

“There is plane to the swing,” Indians hitting coach Ty Van Burkleo said. “It’s just he catches the ball very deep and he has the ability to accelerate to the ball very deep, which allows for low trajectory, high velocity balls off the bat. The more you catch the ball out front, the more you’re going to catch it on that plane.”

According to Statcast, Diaz ranked 15th in the Majors (min. 25 results) with an average exit velocity of 92.8 mph on balls in play, entering Monday. He’s the only hitter on that long list to have a negative launch angle.

The closest right-handed hitter to Diaz on that list is Marcell Ozuna, who currently has an average exit velocity of 93 mph. On balls in play with an E.V. of 92+ mph, Diaz posted a 2.8-degree launch angle, while Ozuna turned in a 19.2-degree angle on the same types of batted balls. The MLB average for balls in play with at least a 92-mph exit velocity is 14.3 degrees.

Here is a visualization of Diaz’s launch angle on BIP with a 92+ mph E.V.

Now, compare that to Ozuna:

The root of the issue, as Van Burkleo noted, is that Diaz let pitches travel deep into the zone before attacking. With that approach, Diaz has a great knack for staying on the ball and hitting it hard, but the result was a 19.1-percent pull rate (lowest in MLB among hitters with at least 50 plate appearances) and a 38.1-percent opposite-field rate (13th-highest in MLB).

Within that, one thing Diaz did exceptionally well was limit himself to pitches in the strike zone. He only swung at 16.1-percent of pitches outside the zone, marking the third-best rate in baseball (min. 50 PA).

In the face of a low batting average, and a lot of hard-hit outs, Diaz stayed with his approach. That impressed Van Burkleo. During a young player’s first experience in the big leagues, the temptation to tinker in the midst of a slump is strong. Diaz never gave in in that regard.

“I never saw him get anxiety or pressing,” Van Burkleo said. “That’s nice to see that he’s got the maturity to stay the course and trust his swing and trust that it’s going to work out over the long haul.”

Over the long haul, Indians manager Terry Francona believes Diaz’s approach will lend itself to improved pull-side power. Like Brantley, Francona said he did not believe in trying to do something different to create an improved launch angle. The manager said improvement in that area will come with experience.

“I know there’s a big new push for the launch angle and stuff,” Francona said. “I love to see, like Yandy hit the ball hard and he hit the ball hard the other way. For guys to do that, you know how often I say it, you’ve got to be doing a lot of things right to do that.

“I think with experience and at-bats, I think guys learn what they can get in the air — things like that. I think if you try to change somebody’s launch angle — you hear that all the time now — I probably have a differing opinion on that than maybe a lot of other people. I think you learn how to hit, and I think Yandy has a really good idea.”

There are a few examples of Francona’s thought process inside Cleveland’s clubhouse. One is shortstop Francisco Lindor, who is in his third season in the Majors now.

If you look at his yearly progression, Lindor’s fly ball rate is climbing as he gains experience. While this season remains in the “small sample size” category, Lindor’s fly ball rate is up to 52.5 percent. That’s a jump from 28.4 percent last year. Likewise, his groundbal rate has dropped to 29.5 percent this year, compared to 49.2 percent in ’16 and 50.8 percent in ‘15.

Along with those changes, Lindor’s opposite-field percentage is also going down: 17.7 percent (2017), 25.3 percent (2016), 29.3 percent (2015). His launch angle to the pull side has also improved: 17.8 degrees (righty) and 15.9 degrees (lefty) in ’17, compared to 2 degrees (righty) and 3.2 degrees (lefty) in ‘16.

“I’m not trying to hit the ball in the air,” Lindor said. “I’m just trying to swing at good pitches, swing at better balls in the zone, not trying to do too much, not trying to hit home runs. Whatever happens after that, happens.”

Another example is Jason Kipnis. Last year, the second baseman set career highs in home runs (23) and slugging percentage (.469). His spike in power stemmed from his altered approach on inside pitches. Per Statcast, Kipnis had a .743 slugging on pitches over the inner-third of the strike zone in ’16, compared to .593 in ‘15.

“He’s going to learn how to do it, too,” Kipnis said. “I think when you come up and you’re trying so hard to not strikeout, you’re trying so hard to put it in play and have a good at-bat, you don’t take as many risks. You worry about just making good hard contact. He’s obviously great at doing that.

“I think when he gets into hitter’s counts and gets some favorable pitches, I think he’s going to learn how to do a little bit more damage.”

That gets to the heart of what the Indians want Diaz to work on.

Here is a look at the heatmap for balls in play by Diaz. Notice something?

Diaz didn’t do much damage on fastballs middle or middle-in during his time in Cleveland. His best skill was going the other way with low or low-and-away pitches. He showed that right out of the gates with his double into the right-field corner off Yu Darvish on Opening Day.

The overall MLB average is .312 and the slugging is .539 on fastballs middle and middle-in this season. The average exit velocity on balls in play is 91.4 mph and the average launch angle is 14.4 degrees. Diaz had a great E.V. on such pitches (97.2 mph), but his launch angle was -17 degrees.

Here’s a look at what Diaz did on middle/middle-in fastballs:

Francona said the last thing usually to come for a young hitter in the Majors is the pull-side power. Diaz’s current approach wasn’t conducive for a lot of slugging percentage to left field. Van Burkleo said the rookie’s swing plane will generate lift, but Diaz has to catch certain pitches out front, rather than letting them travel so deep into the zone.

It’s about picking the right time to do it.

“It’s understanding how to anticipate a ball in,” Van Burkleo said. “They’re going to start throwing more balls in to a guy that’s so efficient hitting balls away. They’re going to say, ‘OK, let’s figure him out. Let’s throw him in.’ You’ve got to have an answer for that.”

Two springs ago, that was a major focus for Kipnis, who had earned the reputation of being a great opposite-field hitter. In the cage, Kipnis would set up the tee inside and out front and focus on attacking that type of pitch. The second baseman would also have Van Burkleo or assistant hitting coach Matt Quatraro flip balls to that specific area. The whole idea was to reinforce the idea of picking times to anticipate that pitch and attack it.

“It improves with experience, because people work on it,” Kipnis said. “He’s got that kind of approach you teach when you’re younger of letting the ball travel, seeing the ball, staying through it the other way. That’s why you see a good strikeout-to-walk ratio with him. It’s because he’s got great hand-eye and great approach.

“I think what you want out of a guy like him is that, yes, he hits the ball extremely hard, but it might be a pitch right down the middle that a guy his size might be able to do more with than fire it at the second baseman. I’ve had that problem before with certain stuff.

“I don’t think they want to eliminate that aspect of his game by any means. I think they want to add to it in the sense that middle, middle in, instead of staying through it, trust yourself and throw the hands at it and do some damage with it to left field.”

Diaz had 15 balls in play with 100+ mph exit velocites, but none cleared the fence. The bulk of those hard-hit balls were singles to the shallow portion of the outfield or lineouts:

There are hitters who are trying to get the ball in the air more these days. It’s been called the “Josh Donaldson School of Hitting” by some. J.D. Martinez has been very vocal about it. Even this spring with the Indians, Richie Shaffer (at Triple-A Columbus) spoke at length about how he overhauled his swing to generate more fly balls. The general idea on that front is that a hitter’s OPS is in the air.

There is a lot of truth to that, but the Indians do not want Diaz to change much with his swing. It’s all about pitch selection and knowing when to go on the attack. That is what Brantley means when he says he doesn’t “believe in launch angle. He doesn’t believe in manipulating a swing in order to create more lift. The lift will come naturally with a better approach.

Think of it this way: Pitchers can form bad habits if they’re focusing too much on pitch velocity in-game. If a hitter gets too caught up in focusing on launch angle, Brantley believes it can have a negative impact.

“I’m all about learning counts, learning situations, learning pitchers’ tendencies,” Brantley said. “It’s having the repetitions so you’re able to attack at certain points or getting mistake pitches, or learning what they’re doing and not trying to do too much.”

Brantley is confident Diaz will get there.

“He uses the whole field,” Brantley said. “I feel like the longer you stay on baseball and continue to let it travel, the better chances you’ll have to square it up. That’s why he hit balls hard. He has a great thought process, a great plan and he’s going to be a great Major League baseball player.”

— JB