Teammates have long stopped laughing at J.D. Martinez and his iPad.

Boston’s All-Star slugger is serious about every swing he takes, even in batting practice, and he has the tape to prove it. Get to the park early enough for Red Sox BP, and you’ll see a pair of iPads attached to tripods, one on each side of the batting cage. When the 30-year-old Martinez steps up, video coordinator Billy Broadbent will point a third iPad at the batter’s box — Martinez’s personal device, which he’s used to record his practice cuts since 2015.

This is an incredible use of technology for a major star.