MVR stands for “mound visits remaining,” a constraint on coaching staffs introduced by Major League Baseball in 2018.
That season, MLB began limiting teams to six mound visits per nine-inning game, then adjusted that downward to five mound visits per nine-inning game for 2019 season.
Coaches or managers may visit the mound once per inning (up to the five-per-game limit) for up to 30 seconds at a time. Exceeding the time limit or making a second visit in an inning necessitates making a pitching change.
Many major league scoreboards began tracking mound visits remaining right alongside ball, strikes, outs, runs, hits, errors, and innings played in 2018.
Suddenly, fans were asking, “What is MVR in baseball?” … and now you know!