You don’t have to understand an NFL playbook to realize rookie quarterback Robert Griffin III possesses big-play potential. From watching the speedy, strong-armed Griffin work, his ability to improvise is clearly the best thing he brings to the Redskins. And at this stage of his development, it’s also the worst.

Griffin’s athleticism often will enable him to elude the pass rush and extend plays. The longer Griffin stays upright, the better chance he has to team with receivers for big gains. Trouble is, all that extra running also increases the potential for big losses, turnovers and injuries.

Griffin must learn when it’s appropriate to take chances or simply play it safe by being sacked or throwing the ball away. For the Redskins’ fortunes to improve, he’ll have to master the concept — and the sooner the better. Although Griffin’s NFL education will continue until his retirement, lesson No. 1 is about the need to protect the football. Not surprisingly, Griffin has shown he needs much more time in the classroom.

After breezing through his brief appearance in the preseason opener against the Buffalo Bills, Griffin had his first taste of professional adversity in last week’s 33-31 loss to the Chicago Bears. He held the ball too long, contributing to being sacked three times. He absorbed unnecessary blows while toeing the sideline waiting for receivers to break free. The capper on Griffin’s what-not-to-do performance occurred late in the opening quarter.

With the Redskins at their 17-yard line, Bears strong safety Major Wright blitzed. Griffin made a nifty, quick move to his left to avoid the sack. He lost his balance in the process, however, and should have just dropped to the ground. The Redskins would have still had the ball on second down.

Instead, Griffin also made the mistake of holding the ball away from his body while he continued to survey the defense. Spotting running back Alfred Morris to his left, Griffin, who was in no position to make an accurate pass while falling, motioned to throw, then fumbled when defensive end Israel Idonije jumped him from behind. The Bears recovered the ball. Two plays later, Chicago scored a touchdown and went ahead, 14-0.

Following his 14-play debut, Griffin made the mistake of saying practice was harder than facing the Bills. Apparently, Bears are meaner. “You just move on from those kinds of things,” Griffin said of his much-tougher-than-practice outing against Chicago. “Learn from them.”

Griffin at least gave the Redskins a chance to continue the play, his fans would say. Again, though, that’s the problem: Having the ability to do something doesn’t necessarily mean you should.

“As a player, especially the type of player he is, he’s gonna always have it in his head, ‘I gotta make the best out of every play,’ ’’ wide receiver Santana Moss said. “But in this league, when he gets the experience of being out there, he’ll realize that the stuff he did in college ain’t gonna always work because these linemen and linebackers are fast, man.