"When Marino came out in the draft, the same year that Elway and Kelly and that group came out, a lot of people said, 'Boy, he's got a funny motion, and we're going to have to change it,'" Kennan said. "He had the ultimate quick release, and you couldn't sack him."
Where Brady fits: Experts gave Brady high marks in this category, but he has plenty of company.
Levy, who earned an advanced degree from Harvard, described the Columbia-educated Luckman as a brilliant man who made the T-formation what it has become.
Numerous others have played the position with intelligence, but brainpower doesn't always translate to football smarts.
"It isn't test score, it isn't book intelligence," Haley said. "Some of those guys, they've just got a feel for the whole thing, and they read [defenses] faster than anybody; they throw it quick, and it's out and it's there, and nobody has moved on the other side of that line."
Where Brady fits: Experts struggled to find a quarterback with better mechanics. Brady clearly ranks among the very best.
Mechanics aren't everything. Layne, Baugh and more than a few old-timers delivered the ball with wild throwing motions. The passing game was in its infancy. Teams didn't employ quarterbacks coaches.
A low release point didn't stop Sonny Jurgensen from passing for more than 30,000 yards during a Hall of Fame career with the Philadelphia Eagles and the Washington Redskins. Favre sometimes delivers the ball with accuracy despite stepping awkwardly to the side or retreating. Marino could do that, too.
They are the exceptions.
"If you look at the great ones, that ball is in the middle of their chest [when they drop back and prepare to throw]," Bratkowski said. "The top of the ball is at the top edge of the numbers because now they can athletically move in any direction."
Brady's mechanics might be as sound as those of any quarterback of any era, experts agreed. Kennan singled out Ken Anderson and Steve DeBerg as quarterbacks known for strong fundamentals. Montana, Young and Starr also stood out as technicians, as did Kelly.
"I have recall of Joe Montana throwing that touchdown pass in that two-minute thing against the [Cincinnati Bengals] in the Super Bowl, a slant route to John Taylor, who was in the slot," Bratkowski said.
"Every time I looked at it, I looked at Joe's feet, and he came off of his foot rhythm and threw the ball perfect for a touchdown. That's what it takes, time after time after time. You deviate, and you are in trouble."
Where Brady fits: Brady throws every route with accuracy, but experts did not single out a specific one.
Luckman, Baugh and Bob Waterfield set the early standard for the deep ball. Van Brocklin, Bradshaw, Namath and Daryle Lamonica took over from there.
Aikman's ability to throw any route perfectly produced what scouts still consider the finest predraft workout by a quarterback in NFL history, a performance that cemented Aikman's status as the first overall choice in 1989.
Elway could scramble to one side, stop, set his feet and throw back across the field before defenders could react. Levy singled out Marino for throwing comeback routes as well as anybody, but there have been others.
"John Brodie could throw sideline passes as good as anybody I've ever been associated with," Meyer said of the 1957-73 San Francisco 49ers quarterback. "He could really throw that and throw it accurately."