The smallest of tweaks can make a difference. For example, offensive coordinator Jim Caldwell, Flacco's former quarterbacks coach, worked with him to improve his knee flexion last season. Bending his knees more benefited Flacco, particularly in the playoffs.

Brenkus said Flacco's kinetic-linking chain is one of the most efficient in the NFL. His release time takes roughly .37 of a second, which is about .03 of a second faster than the NFL average. And when the ball leaves his hand, it can travel 18 yards in about two-thirds of a second. He has been clocked throwing a football at more than 60mph.

"Joe has the God-given talent to throw the football," Jaworski said. "Probably what people don't look at is the complete set of mechanics that it takes to throw the football with that kind of velocity. He sticks his cleats into the ground. He drives off his back foot. He's on balance, for the most part, on almost every throw. … When Joe has a clean pocket, his mechanics are outstanding."

Developing consistency

Not long after Cam Cameron was named offensive coordinator in 2008, the Ravens sent him, then-quarterbacks coach Hue Jackson and a small delegation of scouts and decision makers to "go look at this kid over in Delaware," Cameron said.

They met Flacco at a field that had no lines painted on it and had just been aerated. It was a little windy, "which is perfect to work a guy out in when [you play] in that division," Cameron said, referring to the AFC North. They asked Flacco to throw a bunch of balls he never had used to a handful of receivers he was unfamiliar with. Only one pass hit the ground in the 90-minute workout.

Because Cameron wanted to install a vertical passing attack, he paid close attention to how Flacco fared on fly routes, posts, deep comebacks and other downfield routes.

"He was spot-on," Cameron, now the offensive coordinator at LSU, said in a phone interview this month. "Anyone who was at that workout knew one thing: that this kid was the real deal."

At the end of the grueling workout, Flacco was asked to stand with his feet parallel and throw the ball as far as he could. Flacco maxed out at 73 yards, the second-best mark for any quarterback Cameron has ever worked out.

"That told you right there that he had innate arm strength," Cameron said. "It was one of the two most impressive workouts I had ever seen. The other was Ben Roethlisberger."

Awed by Flacco's arm and his potential, the Ravens took him in the first round of the 2008 NFL draft.

Five years later, Flacco threw 11 touchdown passes and no interceptions in the playoffs, helping the Ravens win their second Super Bowl in 12 years. The Ravens rewarded him with a six-year, $120.6 million contract that, at the time, made him the highest-paid player in NFL history.

No quarterback went deep more often last season than Flacco, who threw the ball 20 or more yards on 17.3 percent of his attempts, the highest percentage in the league, according to Pro Football Focus. On those plays, Flacco had 11 touchdowns and no interceptions, best in the league in both categories.

Last season, the offense was as explosive as it has ever been, setting a franchise record with 72 plays of 20 or more yards. Only New Orleans Saints quarterback Drew Brees completed more passes for 25-plus yards than Flacco.

"Oftentimes you may find [receivers] that can stretch the field, but guys can't get it to them consistently," Caldwell said. "Joe can."

Flacco said this month that he doesn't do anything special to work on his arm strength.

"You throw the football a little bit and get your core [strengthened] a little bit, but I don't think there's really doing too much to my arm strength at this point," Flacco said. "It is what it is, and hopefully it will stay like that for the next 12 years and I won't have to worry about it."

While Flacco might not yet be viewed as being on the same level as former league Most Valuable Players such as the Green Bay Packers' Aaron Rodgers, New England Patriots' Tom Brady and Denver's Peyton Manning, Jaworski says there is no debating which quarterback has the NFL's most formidable fastball.

"Maybe on a good day, Aaron Rodgers can get to Flacco. Matthew Stafford has a big-time arm. Michael Vick can really spin it," Jaworski said.

"So those are the guys that immediately pop to mind, the strong-armed guys in the NFL. … I believe [Flacco] does have the strongest arm in the NFL."