When Nolan Arenado and Paul Goldschmidt arrived at spring training in 2022 with new bats in tow, the few who noticed the difference barely sent ripples through the clubhouse.

A year later, the engorged, hockey puck-esque knobs have become a wave, with at least 10 Cardinals carrying at least a few among their bat supplies entering 2023.

Trends catch in baseball much the same way they do in broader society, but this new collection doesn’t bear much resemblance to Beanie Babies. For as much as advancements in pitching methodology have accelerated in recent years, technology for hitters has lagged slightly behind. Sensing an opportunity, bat manufacturers are looking to close that gap.

Brendan Donovan, fresh off a season in which he finished in third place in the National League Rookie of the Year balloting and won the first ever Gold Glove for an NL utility player, headed to the Marucci Sports facility in Baton Rouge, Louisiana, within a week of the end of the season. While still in hitting shape, he wanted to dive into the tools of his trade and his chain of motion in order to triple check he was doing everything possible to give himself every potential edge.

It didn’t hurt that his trendsetting teammates won (Goldschmidt) and finished third (Arenado) in MVP voting after making their own transitions.

“It was awesome,” Donovan said, repeating himself for emphasis. “It was awesome. Just learning how my body works, what bat works for my body. It’s a little different being a right-handed thrower and a left-handed hitter. We need certain things. I think this knob helps me big time to keep a better connection with my body.”

The physics inherent in a counterweighted bat knob have in many ways been understood for as long as the game has been played. Any little leaguer whose coach has instructed them to choke up for better bat control has at least felt some of the comfort and speed that comes with adjusting the position of hands on a bat handle.

Cardinals manager weighs in

Barry Bonds, after all, set the career record for home runs. Among other innovations, his bat knob was frequently wrapped in several layers of tape and grip enhancement, emphasizing that balance as the barrel attacked the zone. Still, it took the right group of hitters seeking out new solutions for the manufacturing to catch up to the desire.

“I think (Arenado and Goldschmidt) impact a lot of different areas,” manager Oliver Marmol said. “Does it surprise me that there’s others that are curious as to, hey, what’s that all about, and then go and get measured themselves and go through that process of understanding? No, not at all.”

Those who have gone in for a bat fitting have described the process as similar in many ways to purchasing a custom set of golf clubs. The swinger is measured, their body is analyzed, and technicians at the facility offer a variety of options for test swings before landing on the proper model.

Not all of the players with the new bats have gone in for a proper fitting, but each of Dylan Carlson, Paul DeJong, Moisés Gómez, Andrew Knizner, Oscar Mercado, Lars Nootbaar and Tyler O’Neill have included them in their bat collections, along with Arenado, Donovan and Goldschmidt.

Donovan, who described himself as “a nerd,” spent part of the 2020 pandemic break diving into data on his own swing and integrating technology like Blast Motion sensors into his work. The instant data readouts can be immediately brought into a workout.

More on Donovan

The process sounds complicated, but the core is very simple — was that swing harder than the one before it? What change did the hitter make to achieve that result? Is that change repeatable?

For Donovan, the key word is “sequencing.” Stopping in the middle of his walk back to the clubhouse following late infield work, he contorted his body in slow motion to demonstrate the various parts of his swing.

As he explained, “it’s your lower half, turning it, and obviously the barrel is the last thing to go. So if you can swing with better sequence, it’s more efficient, and you create more speed.”

That is where the extra weight in the bat knob comes into play. A successful swing has to be fast in order to generate power, but the barrel of the bat has to stay in the zone for the greatest possible number of microseconds to maximize the chances of good contact. The counterweight adds a whip effect, snapping the barrel through the hitting area at an ideal point in time and space.

Leaving no stone unturned

Sounds complicated. Feels simple.

In addition to changing up his bat, Donovan spent the winter at the team’s Florida complex breaking down other aspects of his biomechanics under the guidance of new assistant hitting coach Daniel Nicolaisen. He’s running now with new insoles in his cleats, designed to optimize his stride pressure. The changes aren’t designed to completely switch up a skill set which has proven successful; he’s simply trying to sand down the rough edges.

“I just didn’t want to leave any stone unturned,” Donovan said. “There’s some things in my game that I want to keep the same. But there’s some things that, you know, maybe if I can find a bat that works for my body, or clean up my running, or my feet to get more carry on my throws, whatever it is.”

Some of the oldest answers can come from the newest questions.