Yankees Manager Aaron Boone’s theatrical run-ins with umpires this summer might have surprised more than a few observers, given his otherwise mild-mannered demeanor. Still, the second-year manager’s mastery of the jabbing index finger, the in-your-face stance and a willingness to get ejected has earned roars of approval from Yankee Stadium crowds.

But as charged up as Yankees fans have been with Boone’s fiery side, he isn’t all that impressed with himself. Asked to grade his most talked-about performance, a July 19 outburst in which he told a rookie umpire his Yankees hitters were “savages in the box,” Boone gave it a mere “B … maybe.”

“I’m actually not overly confrontational or a yeller,” he said. Still, Boone’s antics have stood out in an era in which the wild, drawn-out arguments between hysterical managers and antagonistic umpires have been reined in and toned down.

Despite the introduction and expansion of instant replay in the last decade, the number of ejections in M.L.B. has remained steady. Some data suggests an influx of younger, less-tolerant umpires could be propping up those totals. Another factor is the computerized box that now defines the strike zone on game broadcasts, which has led to steady bickering from the dugout; these days, ejections are more often borne out of disagreements over ball-and-strike decisions than blown calls on the bases.