Earlier in his career, whenever he fell behind in the count against some of baseball’s best hitters, the Houston Astros ace Justin Verlander would do some on-the-mound calculus. He would often opt to fire a down-and-away fastball, willing to concede a single rather than something worse — “Here you go, take your hit to the opposite field.”

But recently, even those pitches have started flying out of the ballpark.

“You have to miss bats now,” Verlander said. “The game’s changed.”

Pitchers’ targets have changed, too. The universal edict among pitching coaches, from Little League up, is to implore their charges to throw strikes. But more and more in the modern big leagues, that doesn’t mean throwing the ball in the strike zone.

The result is a pitching paradox in the majors: Even as M.L.B. is on a pace to set a strikeout record for the 14th straight season, the rate of pitches actually thrown in the rule book zone has decreased almost as consistently.