Shortly after the 2012 NFL draft begins Thursday at 8 p.m., Stanford’s Andrew Luck is expected to walk across the stage at Radio City Music Hall in New York to shake hands with Commissioner Roger Goodell as the top overall selection by the Indianapolis Colts.

Robert Griffin III, the Heisman Trophy-winning quarterback from Baylor, will have his moment in the spotlight soon thereafter, when, barring the unforeseen, the Washington Redskins make him the second overall pick.

This NFL draft is about the quarterbacks in line to be chosen first and second, and the night almost certainly will begin with Luck and Griffin hailed as the next greats at the sport’s most important position, the centerpieces of their franchises for years to come.

The outcomes of past NFL drafts, however, show that events are unlikely to play out quite that way, that the immense promise of Luck and Griffin probably won’t be fulfilled by both men. Draft history indicates that for every Drew Bledsoe, Peyton Manning and Donovan McNabb among the group of quarterbacks selected first and second in the same NFL draft, there is a Rick Mirer, Ryan Leaf and Tim Couch.

“It’s not surprising,” former Colts general manager Chris Polian said recently, going over the list of quarterbacks previously taken first and second in the same year. “It’s basically around 50 percent, historically, no matter where you’re picking in the first round.”

Two quarterbacks have topped the draft charts only four times since the NFL and AFL combined their selection processes in 1967. On three of those occasions, one of the two quarterbacks failed to have the successful NFL career predicted for him.

That was the case with Couch, the Kentucky product taken by the Cleveland Browns with the top overall selection in the 1999 draft, before McNabb was picked second by the Philadelphia Eagles (and Akili Smith went third to the Cincinnati Bengals). It was certainly true of Leaf, the second pick by the San Diego Chargers in 1998 after Manning went first overall to the Colts. And the same thing happened to Mirer, the second choice in the 1993 draft after Bledsoe was selected first by the New England Patriots.

Only in 1971, when Jim Plunkett went first to the Patriots and Manning’s father, Archie, went second to the New Orleans Saints, did both quarterbacks have productive NFL careers. Another successful NFL quarterback-to-be, Dan Pastorini, was taken third by the Houston Oilers that year.

Several experts said they expect Luck and Griffin to break the trend.

“I think these two are going to turn out the way we expect,” said former NFL quarterback Warren Moon, a member of the Pro Football Hall of Fame. “Maybe with some of those guys in the past, there were a few flaws. I don’t see that with these two guys. They’re both highly talented physically. They’re both intelligent. They’ve both got engaging personalities. They’re leaders. They’ve both taken their programs to high levels, elevated their teams. Now they both have the chance to do the same thing again at this level.”