Perhaps the hardest job in the NFL is evaluating quarterbacks.

The Falcons nailed that assignment in 2008 when they selected Matt Ryan with the third overall pick.

Other franchises, such as Cleveland, Oakland and Arizona, have continually struck out when trying to land a quarterback.

Then there is the Tom Brady story, when the entire league, with millions of dollars spent on scouting, couldn’t project his greatness. He was drafted in the sixth round in 2000.

Similarly, for the this year's draft, set for April 25-27, there is no consensus on the top quarterback, and the class doesn't appear to be on par with last season's group, which included Indianapolis' Andrew Luck, Washington's Robert Griffin III, Miami's Ryan Tannehill and Seattle's Russell Wilson.

“The thing that is hard to evaluate, we’ll get all the height-weight-speed stuff, but the two muscles you evaluate quarterbacks with are brain and heart,” said Arizona coach Bruce Arians, a noted quarterback guru. “Until you can really get in there and know them, until you can get into a huddle-type situation and not a rehearsed interview, (you don’t know about their brain and heart).”

West Virginia's Geno Smith likely will be the first quarterback selected, but that's not a lock.

USC’s Matt Barkley once was considered a “can’t miss” prospect, but a shaky senior season may have exposed him as a “system quarterback.”

There’s a buzz in some draft rooms about Syracuse quarterback Ryan Nassib.

“There are a bunch of guys who I think will be playing for a long time in this class,” said Arians, who has helped train Luck, Peyton Manning and Ben Roethlisberger over his 20-year NFL career.

Florida State’s E.J. Manuel, Arkansas’ Tyler Wilson and Tennessee’s Tyler Bray also become NFL starters.

“You’re coming off a phenomenal year of quarterbacks, one that doesn’t come around very often, but I would tell you that there are some good players in there,” Kansas City coach Andy Reid said.

Smith was a Parade All-American coming out of high school. He played as a freshman at West Virginia and went on to become the first Mountaineers quarterback to surpass 4,000 yards passing in a season, in 2012.

Smith, who completed 71.2 percent of his passes last season, had some remarkable games. He passed for 656 yards and eight touchdowns in a 70-63 shootout win over Baylor.

He had a 26-13 overall record as a starter.

At West Virginia, Smith showed that he can handle a complex playbook. He had to communicate complex calls at a fast pace, and the Mountaineers normally ran more than 80 plays per game.

“They put a lot on the quarterback’s plate, and I think it’s very underestimated what this kid can do from a football standpoint,” ESPN analyst Jon Gruden said. “He does a lot above the neck as well as making plays with his arm and his mobility.”

Smith can run, but he’s not a read-option quarterback.

“I think he’s as complete from a versatility standpoint as anyone in this draft,” said Gruden, who has studied film of Smith. “He can run 4.55 (seconds in the 40-yard dash). I’ve seen him drive the ball accurately down the field. I’ve seen him throw the ball with touch and accuracy, make quick decisions, and I’ve seen him be dominant at times.”

Smith did have some issues with ball security. He had 32 career fumbles, and some contend that he’s an inaccurate deep passer.

“Ball security is an issue,” Gruden said. “There is no question about that. … I had him on the field, and I was impressed with his deep ball. I wouldn’t buy into that criticism personally. He’s an excellent deep-ball passer.”

Barkley had a productive career at USC, but a leaky offensive line hindered his performance as a senior.

“Barkley’s going to be a starter in the league at some point,” Gruden said. “Obviously, he’s coming off a (shoulder) injury. He’s done an excellent job rehabbing that.”

The biggest question is Barkley’s arm strength.

“I saw him make all the throws personally with my own two eyes,” Gruden said.