If "launch angle" was the catchphrase of 2017, "high fastballs" may be joining it this season.
Proposed as a counterattack to the uppercut swing, high heat seems to be catching on. But for Nationals closer Sean Doolittle, few adjustments were needed. He was firing high heat well before it was in vogue.
"It's how I've always thrown it," Doolittle said. "I came into the league doing that. At the time, I didn't have a great secondary pitch. So the way I would get hitters to chase out of the zone was by climbing the ladder."
Few pitchers reside at the top of the strike zone like Doolittle does, and the left-hander is only climbing higher. He has increased his average fastball height in each of the past four seasons, and he entered Thursday ranked second among MLB pitchers with an average heater height of 3.11 feet above home plate. As hitters drop their barrel and aim for the sky, Doolittle has feasted.
"Five years ago, hitters were fighting to get on top of the ball," said Doolittle, "and so the theory used to be that if you climb the ladder, it would be harder for them to get on top and create backspin. Now you climb the ladder because they're trying to hit under the ball and hit it up into the air.
"The effects have stayed the same; the reasons are the only things that have changed."

Some hitters would rather spit on a chest-high fastball than even attempt to get on top of it. Yankees catcher Austin Romine said his approach against high heat is simple: Don't swing.
"You're not going to be able to get to that up there unless you're cheating to get to it," said Romine, who added that high fastballs have increasingly made their way into scouting reports for Yankees pitchers. "But then you can't hit anything else. The holes for hitters right now seem to be fastballs up and expanded breaking balls down in the dirt."
Doolittle believes that if he does his job and keeps his fastball elevated, a fly-ball hitter can play right into his strength. His deceptive delivery is hard enough for hitters to pick up, but the way his fastball defies gravity and stays above their hands is a true separator.
"It looks like it's 200 miles per hour coming out of his hand," said bullpen mate Sammy Solis. "That's why Sean can throw it by guys at 95 when you see guys out there throwing 98 and getting hit around."
The spin rate on Doolittle's four-seam fastball hovers around 2,200 rpm, right near the Major League average. But Statcast™'s new pitch movement metric, set to be made public soon, paints a better picture of why he's so effective. Doolittle's heater gets nearly four inches of vertical break above average when compared to similar pitches delivered with the same velocity and from the same left-handed release point. Only seven pitchers -- right- or left-handed -- average greater vertical movement on their fastball by this metric, and they include Clayton Kershaw, rising strikeout artist Josh Hader and Marco Estrada. Subsequently, only three active pitchers -- Craig Kimbrel, Chris Sale and Chad Green -- have allowed a lower slugging percentage on four-seamers than Doolittle since the start of 2016.

That kind of success has emboldened Doolittle to go right after hitters. Since the start of 2017, he has gone with his four-seamer on nearly 87 percent of his pitches -- a rate topped only by Rockies reliever Jake McGee in that span.
"He's always been a guy who says, 'Here's my four-seam fastball, go ahead and hit it,'" said Blue Jays first baseman Justin Smoak, an 0-for-7 hitter lifetime against the Nats' closer. "You know it's coming in hard, but when it's elevated like that, it's something that's tough to get to."
But just as Doolittle walks the tightrope as a big league closer, so too is the precarious life of a high-fastball practitioner. Rockies first baseman Ian Desmond's game-winning homer off him on April 15 was an example of how precise the lefty must be.
"There's a buffer zone where I don't want to be," Doolittle explained. "The pitch I threw Desmond ended up there -- right around the thigh. That used to be considered a high fastball. A ball in that buffer zone gives a hitter the best chance, and if it's a guy who's looking to hit it in the air, that's where you're playing with fire."

Doolittle's combination of velocity and vertical movement gives his fastball more margin for error than most. But the countermovement to high heat may already be underway, just below the surface.
"It's a cat-and-mouse chess game," said fellow Nationals reliever Shawn Kelley. "I think you are seeing pitchers who know certain guys are trying that uppercut or that load with their hands, and you're continuing to see them pitch higher and higher. But you also see guys making adjustments, and you notice after a month or two that they're starting to hit balls that are up. We're all chasing each other."
Doolittle has noticed it, too. Occasionally, a hitter will get on top of what he considers to be a perfectly executed heater.
"I do think there's a way to beat [the high fastball], but I won't tell you how," Doolittle said with a smile. "I've had it done to me, and I've gone to my hitters and told them, 'That was really annoying to pitch against. What did they just do?'
"There's a way, but guys aren't getting paid for that style of baseball. They're willing to strike out by taking three chances at hitting a home run."
That's fine by Doolittle. Until hitters adjust, he'll keep winning more battles than he'll lose.