What is a bench coach in MLB?

The experience of four of the seven managers brought in this offseason comes from their time spent as bench coaches, a crucial but little-known position that is now practically required to be a head coach.

The Astros (Joe Espada) and Brewers (Pat Murphy) promoted their bench coaches; the Mets (Carlos Mendoza) hired the bench coach from the Yankees; and the Giants (Bob Melvin) hired a longtime manager who started his managerial career as a bench coach. These four teams made the new hires.

Four out of seven is about average for the league, where 18 of the 29 current managers were bench coaches before taking over as captains. And a lot of them quickly achieved success after taking that risk.