According to the linear weights that form the basis of so much sabermetric theory, a walk is worth .55 runs compared to an out, a single is worth .70. And that of course ignores the fact that swinging the bat might also result in a double, triple or HR. https://www.fangraphs.com/library/principles/linear-weights/ Of COURSE a single is worth more than a walk. That’s not even debatable. Mauer taking a walk with runners on often ends up leaving the task of driving in those runs to someone that most of you would describe as not as good a hitter as Mauer. And despite the current dismissal of RBI, SOMEone has to drive in those runs. They don’t add up base runners at the end of the game and declare a winner, they add up runners who actually crossed home plate. Walks are fine. They are not the objective, and in the case of Mauer, comprise too much of his OPS. He’s worth less offensively than players with equal or even a little lower OPSs.