BALTIMORE — Jarrod Dyson got a new haircut for the postseason. Dyson, the Kansas City Royals’ speedy reserve outfielder, had the outline of a four-letter word, in all capitals, buzzed just above his right ear: ZOOM, it says.

“That’s what I’m going to do tomorrow,” Dyson said at Camden Yards on Thursday.

He is probably not kidding. The Royals had the most stolen bases in the major leagues this season. The Baltimore Orioles, their opponent in the American League Championship Series, had the fewest. The Orioles, however, hit the most home runs in the majors. The Royals — you guessed it — hit the fewest.

Contrasts don’t get starker than that, but these franchises have one big thing in common: a decades-long yearning for a championship. The Royals have the most losses in the A.L. since 2000, and the Orioles have the second most. Both have built patiently for this moment, for a chance at their first World Series appearance since the 1980s.