The pitchers are ready to dig a moat around the mound. They feel under siege. There are limits on mound visits. There are limits on time between pitches in the minor leagues. There are limits on warm-up tosses between innings. The strike zone has tightened up. The baseballs have wings. Sean Doolittle, a Washington Nationals relief pitcher, once heard a proposal limiting how many relievers can pitch in one inning, just to make sure the game moves along at a brisk pace.