Let's start with a disclaimer.
Only Jay Cutler and his doctors know exactly how many concussions he's suffered. But, in reality, some people can have a concussion and not even realize it. So there's a lot of gray as it relates concussions and blows to the head.
Much has been made, though, about Cutler and concussions.
When asked directly on Wednesday, Cutler said the concussion against the New York Giants Oct. 3 was his first ever.
But there are previous reports that suggest there may have been more.
In November 2004, the Tennessean in Nashville reported that Cutler suffered a concussion Sept. 20, 2003 in a 30-14 loss to TCU.
"I was pretty messed up," Cutler told the paper with a laugh. "I was calling the wrong plays. The funniest thing is they were just like, 'All right, ready, break,' and going out there and doing it. Everybody knew it was wrong, but they ran the plays anyway. It was a mess. I don't remember the second half at all."
In a separate summation of Cutler's injuries, the Tennessean reported that he had three concussions but didn't elaborate.
But, in an Oct. 19 story, the Tennessean reported that Cutler left in the third quarter of a game against the University of Georgia with a "mild concussion" but returned to finish the game.
A Vanderbilt spokesman declined comment to the Sun-Times Thursday, citing federal HIPAA law.
Five different NFL general managers and personnel executives told the Sun-Times that their respective clubs did not red-flag Cutler because of head injuries when he was coming out of Vanderbilt.
If there really were three documented cases, though, NFL teams would have been alarmed.
In the 2006 season finale, when he was with the Denver Broncos, Cutler was knocked out of the game when he was drilled by then San Francisco 49ers defensive tackle Anthony Adams in the second quarter.
The Broncos replaced Cutler with veteran Jake Plummer. But Plummer was 0-for-2 with an interception. In the second half, Cutler returned to the lineup.
"If he wasn't well, we wouldn't have put him in," said then Broncos head coach Mike Shanahan, who added that doctors cleared him to play.
According to the Denver Post, Cutler said he was he was "a little dinged up."
"My head was swimming a little bit," Cutler said at the time. "I cleared up and I was fine in that second half."
It was a pivotal game for the Broncos, with a playoff spot on the line, and Cutler led the Broncos on an 80-yard touchdown drive in the fourth quarter that tied the game 23-23.
But the 49ers won the game in overtime.
Cutler did leave the game, after the hit by Adams. But was it a concussion?
By definition, according to the Mayo Clinic, a concussion -- no matter the severity -- injures the brain.
"Concussions range in significance from minor to major, but they all share one common factor -- they temporarily interfere with the way your brain works," according to the clinic's website. "They can affect memory, judgment, reflexes, speech, balance and coordination."
Also, it would be hard to imagine the Bears approving a trade for a player with four documented concussions. As they showed in September, when they proactively placed linebacker Hunter Hillenmeyer on the injured reserve, the Bears take the matter of concussions very seriously.
And per a new NFL rule, the league has set up a checks and balance system to ensure players are not rushed back too soon from concussions. In addition to team doctors, a player must get approval from an independent neurologist before he returns to the playing field.