Gwynn was hard-working and renowned for his work ethic and devotion to extra batting practice. On the road, he stayed in his hotel room, studying video of his at-bats or playing video games. In an era before laptops and tablets, Gwynn bought his own video equipment and lugged it from town to town along with tapes of his games. His wife traveled with a Betamax video cassette recorder that was the size of a suitcase to tape his at-bats. Still, the Padres were the last MLB team to hire a video coordinator. Gwynn later invested in close to $100,000 in video equipment that he shared with his teammates. Few hitters were as meticulous as Gwynn with his detailed notebooks and videotape, which he spent hours studying. He studied pitchers, watching them in the bullpen and on television or video, to learn their tendencies on every count. He spent hours watching video and analyzing his swing frame by frame. He had one tape of each team, which included his at-bats against that team in the season. "Tony taught me more about hitting than I ever taught him", said Merv Rettenmund, his hitting coach for nine years with the Padres.