This is Alex Stumpf’s sixth piece as part of his May residency at FanGraphs. Stumpf covers the Pirates and also Duquesne basketball for The Point of Pittsburgh. You can find him on Twitter, as well. Read the work of previous residents here.

Lowering the hands has become the “have you tried turning it off and back on again?” of the baseball world. Eric Thames lowered his hands and was one of the hottest hitters in April. Aaron Altherr lowered his hands and has been one of the hottest hitters of May. Miguel Sano, Jean Segura, Jake Lamb and plenty of others have done the same. If your favorite team has a slugger who’s broken out in recent years and you want to know why, check if his hand position has changed. Chances are it has.

Mechanically, it makes sense as to why it’s catching on. According to Phillies hitting coach Matt Stairs — who’s an advocate for low hands — when a batter goes to the launch position with low hands, he goes straight to the baseball. If the hands are high at the start, the batter has to drop them and then explode to the ball. Lowering the hands eliminates an unnecessary movement and allows the batter to get the ball in the air better. Bat speed also tends to go up, which is a good way to counter fastballs that are getting faster almost every year.

Stairs lived through the struggles of having poorly positioned hands during his major-league career. In his days as a pinch-hitting extraordinaire, he liked having his hands chest high. When they rose, that’s when his trouble started.

It took Stairs 10 years before he finally figured out how to keep his hands in the right spot. When he started his first spring training as a hitting coach this year, he had a simple message to his young pupils: “Don’t take as long as it took me to figure it out.”

Recently, Stairs noticed that, during Maikel Franco’s slump, his hands were too close to his face. They worked on lowering them again, and Franco rattled off hits in eight consecutive games after making the adjustment. Franco didn’t know they were a problem until Stairs spotted it.

So who could refute a swing change that is tailor-made to generate more bat speed, fly balls, and most likely more offense? Enter: Pete Rose.

Regardless of what you may think about him, Rose knows a thing or two or five about hitting. During the postseason last year, he, Alex Rodriguez and Frank Thomas each talked about his swing and against what pitches they each struggled. As expected, hand position was brought up. The first two minutes are the most important to this post, but if you want to hear three players with almost 10,000 hits between them talk about hitting, the whole segment is well worth your time.

Rose contradicts himself a tad by saying a batter shouldn’t change his swing, but then credits the location of his hands as the difference between pulling a pitch or trying to send it to the opposite field. They are lower when he is trying to pull the ball, meaning he is trying to get through the zone quicker to get out in front of the pitch. Does a change in hands position by itself constitute enough for a swing change? You be the judge. Either way, he was successful and at least thought he had the same approach.

The Mariners’ Taylor Motter is the opposite of Rose. He tinkers with his swing all the time to find something that feels good. Motter changes his hand position based on how often he gets to play. When he was a utilityman with Tampa Bay, his hands were shoulder high. When he was making starts for the Mariners earlier in 2017, he lowered them. Some time after returning to the bench, he rose them again because his timing was off. “Sometimes you have to change with the game, and that’s what I think I’m doing right now,” Motter said. “You have to change it to be the type of person or player you are.”

Motter adapts out of survival. David Freese opts not to change because he’s been consistently successful. At the start of spring training, MLB.com’s Adam Berry wrote that Clint Hurdle told his hitters “your OPS is in the air” and to be mindful of launching points. Freese’s hands start above the shoulders, close to the face. While the league’s ground-ball rate this year is around 44%, his is 52% entering play today. He would probably benefit from lower hands and a higher launch angle. He says that, if he were a younger player, he would probably give it the ol’ college try. But he’s a nine-year vet and has been a good hitter for just about every one of them. He’s satisfied and isn’t going to change what has worked so far.

If 20 players were asked where they should put their hands, there would probably be 20 different answers. Some of those 20 would be willing to change, some not. And how low is low? Motter lowered his hands from shoulder height; others find success lowering it to the shoulders. There’s over 150 years of organized baseball in the books and the general consensus on positioning is best characterized by fictional stock-car driver Ricky Bobby: “I’m not sure what to do with my hands.”

Stairs is an advocate for low hand position, but he preaches a more important lesson: being comfortable with your swing. Altherr is reaping the typical benefits of lowered hands. His bat speed is up. He’s hitting the ball harder. But the greatest change was mental. His bat now sits on his shoulder. “That’s really the big thing that’s helped me relax,” Altherr said. Being able to relax is the change to which he credits his output.

So yes, dropping the hand position made Altherr a more productive hitter, but it also created a middle man that deserves most the credit. He’s confident and comfortable. Just about every hitting coach would agree that comfort is king. It’s why there are Kevin Youkilises and Craig Counsells who succeed despite holding the bats over the heads. As long as they can get to the ball and hit it at a good launch angle, their sins are forgiven.

So what’s the takeaway? Are more players going to lower their hands to get better bat speed and more fly balls? It seems to be pointed in that direction. Is it one size fits all? No. To paint with a broad stroke: batters with lower hands tend to hit more fly balls, but not every hitter needs to be a fly-ball guy. Guys like Motter need to adapt to playing time. Freese and his contemporaries aren’t going to change as veterans unless they need to. The Roses of the game aren’t going to change regardless of if they are hot or in a lull. Then there are the guys like Franco and Stairs who might not even know their hands are a problem. The “right” place to put your hands is always going to be up for debate.