A group of Los Angeles Dodgers hitters descended upon Kent, Washington, this offseason to swing abnormally heavy bats under the watchful eyes of Driveline analysts, all with one mission in mind:
Survive.
Hitting has never been more difficult, a truism that acts as the biggest impediment to Major League Baseball’s determined efforts to increase action. None of the industry’s new rules — not pitch clocks, not shift restrictions, not bigger bases — can change that. Pitchers throw harder than ever, with unprecedented movement, and those who are paid to conquer them are struggling to keep up.
“Nobody understands it,” Dodgers right fielder Mookie Betts said. “Unless you’re a hitter.”
Frustration, though, can often trigger curiosity. And so there was Betts, joining Max Muncy, J.D. Martinez, Gavin Lux and at least a couple of other teammates who took part in Driveline’s weighted-bat program, developed to increase bat speed and, perhaps, give hitters a fighting chance against their sport’s continually rising velocities.
The average speed of four-seam fastballs, sinkers and cutters has either remained flat or increased every year since 2008, starting at 91.2 mph and reaching 93 mph in 2022. With it, strikeout rates have skyrocketed and batting average has plummeted. Leaguewide batting average stood at .271 in 1999 and dropped all the way down to .243 in 2022, the lowest since 1968 — the season before MLB lowered the pitcher’s mound — and the fourth lowest since 1900. The strikeout rate was 16.4% in 2005 and went all the way up to 23.2% in 2021, the highest ever in a full season.
“The problem is there have been so many advancements on the pitching side with velocity, pitch efficiency, all this stuff,” Muncy said. “There’s so many programs they can use. The hitters, we really got nothing.”
Hitters have increasingly incorporated high-velocity machines into their training, some of which can mimic the precise characteristics of every major league pitch. A smaller number — Muncy included — have also visited cognition labs in hopes of training the mind to make quicker decisions. But Martinez believes Driveline’s weighted-bat program might become the biggest development in hitting since the advent of launch angle. He called his most recent visit “an eye-opening experience.”
Driveline, a baseball training facility with wide-ranging influence throughout the sport, has been running some version of the weighted-bat program since it began teaching hitting near the end of 2016. But only recently has the company noticed significant interest from major league players. Close to 30 of them have taken part over the past two offseasons, said Tanner Stokey, Driveline’s director of hitting. It’s a list that includes Nolan Arenado, Lars Nootbaar, Mark Canha, Taylor Trammell and a handful of Boston Red Sox hitters.
After navigating Driveline’s intricate biomechanical assessment process, hitters are given three customized bats developed by the company Axe, each equipped with a blast-motion sensor to track their data. Two are 20% heavier than a standard game bat, one holding most of the added weight on its barrel and the other being more evenly distributed. The other is 20% lighter.
Hitters progress from soft toss to normal batting practice to high-velocity pitching machines, generally working from heavy to light within each drill. The heavy bats strengthen the bigger muscles that are activated during the swing; the light bats train the fast-twitch muscle fibers.
Stokey said major leaguers gain on average between 1.5 and 2 mph of bat speed over the course of an offseason through the weighted-bat program — and that is no small increase, given the time and production elements associated with it.
An average of 0.72 milliseconds of reaction time has been gained for every 1 mph of bat speed by the major league players who have trained at Driveline’s facility, according to the company’s internal research. In 562 instances when hitters gained between 3 and 5 mph of bat speed, an average of 2.46 milliseconds of reaction time came with it. Considering it takes a 100 mph fastball about 400 milliseconds to cross home plate, even the smallest bump could mean the difference between a foul tip and a line drive.
“It’s just going to give you more time,” Stokey said. “And obviously as pitchers are starting to throw harder, time is very, very important to hitters.”
But a higher rate of contact wouldn’t necessitate a sacrifice in power. Quite the contrary, actually. Driveline’s data also states that for every 1 mph of increased bat speed, 1.2 mph of exit velocity is gained. That translates to an extra five to seven feet on a player’s best-hit fly balls. A 2 mph increase can add as much as 14 feet.
“That ball that is just missed and gets caught in the track — if you have a little bit more bat speed, it’s going to start leaving the yard,” Stokey said.
Martinez, the 35-year-old designated hitter who famously turned his career around by adopting the launch-angle principles of Craig Wallenbrock, had a bat speed in the low 70s during the early phases of the program.
“I was like, ‘Yeah, that feels good. That’s good, right?'” Martinez recalled. “They go, ‘That’s terrible for you.'”
Driveline’s metrics place league-average bat speed at 72.8 mph, with elite residing in the 75 mph to 76 mph range. Martinez, the Driveline analysts told him, used to reside in the latter category. Once he didn’t, most of his home runs turned into doubles (he homered 16 times last year, his lowest total in a full season since 2013). At Driveline, Martinez was given a layout estimating that the bat speed of his prime would have provided him with 21 additional home runs.
“And I’m like, ‘Twenty-one plus 16 is what? Thirty-seven — right where I normally am,” Martinez said. “So then I just really dedicated myself to it. I said, ‘I’m going to do this. I’m going to commit to it and see what happens.'”
Over the past decade, the influx of technology, particularly high-speed cameras and radar technology, has been a boon for pitchers, allowing them to maximize spin rates, increase velocity and shape breaking balls. The gap between hitting and pitching widened significantly, but Dodgers general manager Brandon Gomes believes it is “getting closer.”
“Hitting development and hitting training is a couple years behind where pitching is at,” Stokey said. “Three, four, five years ago there was a big debate as far as how important velocity is for pitchers. And at this point it’s widely expected that the harder a pitcher throws, the better their stuff is, the better they’re going to be. We’re basically at that same point with bat speed and guys now accepting the fact that moving the bat faster is generally a good thing.”
Several Dodgers went to Driveline in early December, and a couple of others followed around the middle of January. Most of them took weighted bats home and were given a program to follow throughout the offseason. Stokey encourages players to also hit with weighted bats at least once or twice a week during the regular season in order to maintain progress.
Muncy started at 70 mph, which he partly attributed to still being early in his offseason training, and got all the way up to 77 mph by the end of his session. He’s hoping the uptick, if it sticks, will feel natural.
“A pitcher can throw at max effort, but for a hitter it’s very hard to swing max effort,” Muncy said. “I would say 90% of the hitters out there when they swing max effort their swing actually gets slower. And it becomes worse. That’s the other part of it, too. I think this program can be good because it teaches you how to swing max effort in an easy way.”
Chris Taylor also visited Driveline but mostly bypassed the weighted-bat training, instead focusing on his mechanics, specifically getting his swing plane right in order to cover the four-seam fastball up in the zone. He’s intrigued by the concept but is also worried about how it might mess with his swing.
“I definitely think there’s something to it,” Taylor said, “but I think there’s a happy medium there.”
Betts too said he’s hopeful that programs like this will help hitters catch up to pitchers, but he remains skeptical about how much it can change the course of offensive production in the sport — and about hitting in a macro sense. His biggest takeaway from his time in Washington was that he needed to add strength, so he put on an additional eight pounds of muscle before arriving at spring training last week.
“The game is hard, you know what I’m saying?” Betts said. “People need to lower their expectations a little bit. … At the end of the day, it’s a hundred miles per hour. It’s a round ball with a round bat, and you have to be millimeters precise.”
And the path to getting there can vary greatly depending on the player. It’s why the Dodgers deployed staff members at Driveline’s facility during the weighted-bat sessions. They wanted to see how their hitters responded and gain a better sense of how to maximize each player’s bat speed in the future.
These days, any little bit might help.
“That’s the goal is to increase these things on the margin while adding to elite bat-to-ball and the ability to look over a baseball,” Gomes said. “Any little advantage that our guys can get by improving these small levers is only going to be positive.”
ESPN’s Jeff Passan contributed to this report.