Reversing a long history of being denied the chance to play, black quarterbacks are the most vital change agents of this era of football. But for as much as they may be celebrated, their arrival has stirred a lot of questions not easily answered. The most pressing: If this is a watershed moment in N.F.L. history, what can we expect on the other side of change?

The league, and football in general, has a long history of stacking — funneling players to positions based on racial stereotypes — that kept black talent away from “thinking” positions like middle linebacker and center for decades. Essential to the game itself and to its lore, the quarterback position has been the last role unlocked for black players, who make up 70 percent of the N.F.L.’s labor force, for much the same reason that the other positions finally were: the game had to embrace elite players who are black or face stagnation.

That welcoming has upended stereotypes about black quarterbacks being naturally superior athletes preferable only for their ball-carrying ability and not intellectually strategic game managers.

“This idea that someone doesn’t have the intellectual wherewithal to play the position because of their race has fallen by the wayside, and that’s a positive thing,” said Charles K. Ross, a professor of African-American studies at the University of Mississippi, and the author of “Outside the Lines: African Americans and the Integration of the National Football League.”

Each member of this current generational wave has proved himself a pocket passer, capable of dissecting coverage and wowing that way. But many also run, a lot. Not just clock-managing scampers and fight-or-flight rushes when their pockets collapse either. They sometimes even run right up the middle. The success of such run-pass offenses means that quarterbacks of this era are often running by design, even if the result of those runs seems serendipitous.

The run-pass offense trend has sparked a need for and acceptance of this rise of stategically complex quarterbacks who can make that tactic work.