BOSTON – In the middle of August 2016, Houston Astros center fielder George Springer sent a text message to Boston Red Sox reliever Matt Barnes. They were childhood friends and had played together at the University of Connecticut, so Springer didn’t mind using Barnes as a conduit to ask his Red Sox teammate Mookie Betts for a favor: “Leave a bat.”

The Red Sox were finishing a series in Baltimore. The Astros were headed into town to play the Orioles. In the bat-obsessed culture of Major League Baseball, players are swingers in more than one way. The bat they love one week they’ll happily ditch the next. While some are monogamous, other hitters prefer polyamory with their bats, giddily testing out a wide array in hopes of finding one with some hits in it. And at that moment, Mookie Betts’ 33½-inch, 30½-ounce bat was chock full of them.

Little did either know the Axe Bat model MB50 would play a front-and-center role in both of their ascents to the top of their profession – and in the can’t-miss American League Championship Series, which begins Saturday at 8:09 p.m. ET when the 108-win Red Sox host the 103-win Astros. Springer will lead off the game. Betts will lead off the bottom of the first inning. Both will swing the unique bat, which replaces the classic knob with an axe-shaped handle, because Betts knew Springer, liked him and agreed to leave behind a bat that day in Baltimore.

“I could’ve said no, but I’m not that kind of guy,” Betts told Yahoo Sports on Friday. “He’s a good friend. Obviously you want to go out and win and do everything you can. But sometimes you’ve just got to help a friend out. It may come back to haunt me, but I definitely don’t regret it.”

The week of Aug. 14, 2016, had been perhaps the best of Betts’ AL MVP runner-up season. It started with a 4-for-6, three-home run, eight-RBI day against Arizona. Two days later, he homered twice and drove in five against the Orioles. The day after that, he went 2-for-3 and scored three runs. Before he left town Aug. 17, Betts handed a bat to a clubhouse attendant for safekeeping and told him to deliver it to Springer when he arrived.

View photos Houston Astros center fielder George Springer’s first game using the Axe Bat model MB50 was on Aug. 18, 2016. (Getty Images) More

On Aug. 18, Springer debuted Betts’ Axe with a 1-for-4 night. Finicky types might’ve balked at using it again. Springer stuck with it the next night, hammered a leadoff homer as part of a 4-for-5 showing, went 3-for-4 with another homer and a double the day after and hasn’t stopped using it since.

“It just felt different,” Springer told Yahoo Sports. “I felt like I had more control of my swing for the first time. It could all just have been placebo effect – I tried something new and it worked. I don’t know.”

The genealogy of the MB50 started in 2015 with Dustin Pedroia, the Red Sox’s MVP-winning second baseman, who was the first major leaguer to use the axe handle after the league certified it for in-game use. Players initially regarded the bat as a novelty, though they were intrigued by the claim that it would mitigate the broken hamate bones that stem from knob-handled bats. Springer’s teammate, Carlos Correa, was among the first players to try one, long before Springer became a convert.

“I’d kind of made fun of him for it,” Springer said. “Like, who uses an axe handle? Just as a joke. And I actually picked his up before I got Mookie’s actual bat. I tried it. I was too scared to swing it in a game, but I liked the feel of it.”

One problem with Correa’s bat: It was too big for Springer. Pedroia’s bats are among the smallest bats in MLB. Betts, who like Pedroia is listed at 5-foot-9, said he saw one lying around, picked it up and tried it. It felt good enough that he first used it in a game on Sept. 18, 2015. Before the 2016 season, Betts asked to slightly tweak the size, and Victus, a bat manufacturer that licenses the patented axe handle from the Seattle-based Baden Sports, delivered a batch of MB50s to the Red Sox’s spring camp in Fort Myers, Florida.

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