Launch-angle revolution? Without exit velocity, those fly balls are outs

Now that we can measure the angle at which a baseball leaves a bat, some people have advocated hitting the ball in the air because it turns out — somewhat unsurprisingly — that when you hit a fly ball, you’ve got a better chance of hitting a home run.

So far, so good.

The problem with hitting a fly ball is what happens when you don’t hit a home run.

A recent look at Baseball Reference showed that when the Royals hit a ball with what the website refers to as “fly-ball trajectory,” they hit 58 of their 68 home runs ... but had a batting average of .159.

Take out the 58 home runs, and the 58 at-bats that went with them, and the Royals' batting average on fly balls was .083.

If you’re thinking, "So what? The Royals offense is bad!," let’s take a look at what happens when one of the best teams in the National League hits a fly ball.

At the time this was written, the Atlanta Braves were second in runs scored, second in team batting average, third in on-base percentage and third in slugging percentage.

When the Braves hit a ball with fly-ball trajectory, they hit 87 of their 97 home runs but had a batting average of .221. Take out the 87 home runs, and 87 at-bats and when the Braves hit a fly ball and it wasn’t a home run, and their batting average was .108.

But both the Braves and the Royals excel when they hit a ball with what Baseball Reference describes as “line-drive trajectory.”

Drop-down nets

Kevin Seitzer is currently the Atlanta Braves hitting coach, but he used to be the Royals' hitting coach. When Seitzer was here in Kansas City, he had “drop-down” nets added to the front of the Royals’ batting cage.

If Seitzer thought the players were getting too fly-ball happy and playing home run derby during batting practice, he’d drop the nets so they hung like a curtain and knocked down balls that left the bat on a fly-ball trajectory. The players would have to lower their sights and hit line drives to get the ball out of the batting cage.

It was Seitzer’s way of reminding his players to avoid fly balls and concentrate on hitting line drives, especially when playing in a park the size of Kauffman Stadium.

As bad as the Royals' offense has been so far this year — last in runs scored, 12th in team batting average, 14th in on-base percentage and last in slugging percentage — they still hit .622 when they hit line drives.

The Royals have hit just 10 line-drive home runs but still slug .867 because they hit so many line-drive doubles. The Braves show the same pattern: only 10 line-drive home runs, but a .624 batting average and .899 slugging percentage — because they also hit a lot of line-drive doubles.

Hard, not far

Launch angle is just a fancy term for a batted ball’s trajectory. A batted ball that goes straight up has a launch angle of 90 degrees; a ball that leaves the bat parallel to the ground has a launch angle of 0 degrees; and a batted ball that goes straight down has a launch angle of minus-90 degrees.

Roam around the Internet looking for stories on launch angle and you might run across one from the Washington Post. Published in June of 2017, it says the “sweet spot” for home-run launch angle is 25 to 35 degrees, as long as the exit velocity is 95 mph or greater.

There’s not much point in hitting a ball with home-run trajectory but warning-track exit velocity. Those tend to become outs.

When Pedro Grifol, the Royals' quality-control coach, was asked what was more important — launch angle or exit velocity — he said you need both, but that’s easier said than done.

To get the ball in the air but still hit it hard is tricky; you’re trying to hit the bottom half of the ball and still get enough of it to hit it out of the park.

A recent look at the 50 hardest-hit balls of 2018 showed only five were hit with a launch angle of 25 degrees or greater, and that’s no mystery: It’s easier to hit the ball hard when you hit the middle of the ball with the middle of the bat.

That’s why Grifol thinks a launch angle of 18 degrees is perfect. Seitzer advocates a launch angle of 12 to 28 degrees — low enough to hit the ball hard, high enough to drive the gaps and, when everything is just right, hit the ball out of the park.

But even with a less-than-perfect launch angle, good things tend to happen when a batter hits the ball hard.

In a recent game at Seattle, Royals third baseman Mike Moustakas hit a ball that bounced before getting to Mariners third baseman Kyle Seager. But the ball was hit at 103 mph and turned into a single when Seager couldn’t handle it. Hard-hit balls don’t give the defense much time to react.

Moustakas doesn't think much about launch angle; he believes it wouldn’t pay off in Kauffman Stadium. Moustakas said he just wants to hit the ball hard.

Whit Merrifield agreed: He believes that if you think about hitting the ball in the air, “You’re toast.”

Go back to the list of the 50 hardest-hit baseballs. Thirty of them were hit with a launch angle between +15 and -15 degrees. The guys who hit those 30 balls made 10 outs and hit only one home run, but they also hit five doubles and had a collective batting average of .667.

Numbers like those are why George Brett believed in hitting the ball “hard, not far.”

When Brett preached that to Lucas Duda in spring training, Duda said it clarified his thinking. So far, the results haven’t been as good as he’d like, but Duda feels like focusing on hitting the ball hard is the right approach.

The Royals first baseman said that before a game against the Cleveland Indians and then went out that night and proved his point.

In the first inning, he belted a fly ball with 107 mph exit velocity and homered; later in the same game, he hit a fly ball with 88 mph exit velocity and flew out. The launch angle of either hit would've worked. The difference was exit velocity.

Different strokes ...

As Grifol pointed out, a left-handed hitter who hits a lot of fly balls while playing for the Yankees could take advantage of their stadium’s short right-field porch and be a huge success; the same guy playing for the Royals might be a liability.

There’s no perfect launch angle, in other words; it depends on who you are and where you play.

And despite the launch-angle revolution, Seitzer said he hasn’t changed his teaching. He still believes hitters are trying to do what they’ve always been trying to do: hit hard line drives into the outfield, into the gaps and out of the park.

And the higher (or lower) the launch angle, the more difficult it is to hit the ball hard, because you’re missing the center of the ball.

And without exit velocity, all those fly balls are likely to become outs.