It's pretty clear, when you look at it. The effect Doug Flutie had on Boston College, that is.
"I think Doug's presence here, any historian could go back [and find it]," coach Frank Spaziani said, standing on the Eagles' practice field before a recent session. "All you have to do is look at pre-Doug, when Doug did his thing and after Doug. There's a complete change in BC football and how it's perceived by fans, alumni and people around the country."
That thing that Flutie did? Oh, just come seemingly out of nowhere to win the starting quarterback job and then lead the Eagles into the national consciousness with his particular brand of football. The 5-foot-9, 180-pound Maryland native used a combination of nifty scrambles, long passes and an uncanny knack for the dramatic to pile up record-setting statistics, finish third in the Heisman Trophy balloting as a junior and win the award as a senior.
Oh, and he also threw a certain pass against a certain opponent to win the game as time expired. On national television, the day after Thanksgiving in 1984. You might have heard of it, it's called the "Hail Flutie."
The year after Flutie's Heisman season ended with the Eagles' 45-28 win over Houston in the Cotton Bowl, BC enjoyed a noticeable spike in applications.
"Boston College was always a good school, [it was just] that more people knew about it," Spaziani said of what came to be called the Flutie Effect or Flutie Factor.
While some doubted the veracity of such a thing, subsequent research has shown that the phenomenon does exist.
"Football and basketball success significantly increase the quantity of applications to a school the year following the athletic success, with estimates ranging from 2-8 percent for the top 20 football schools and the top 16 basketball schools each year," Jaren Pope, assistant professor of economics at BYU, wrote in an email.
Pope and his brother, Devin, co-wrote a paper on the phenomenon. Entitled "The Impact of Sports Success on the Quantity and Quality of Student Applications," the paper was published in the Southern Economic Journal in 2009.
The Popes' research showed that football schools tend to enroll more students the year after, while basketball schools tend to select the best applicants from a larger pool.
While the Flutie example is a good one, it's neither the first nor the last. Spaziani remembered the University of Virginia enjoyed its own version thanks to the prowess of one Ralph Sampson, who arrived on campus in 1979 and promptly dominated the hardwood. He won three player of the year awards at UVa. and was the No. 1 pick in the '83 NBA draft. (Spaziani was a defensive backs coach at UVa. from 1982 to 1985.)
"It was like, 'Whoa, what a player,'" Spaziani said of the stir Sampson created. "Just think about it, you're on national TV all the time. All you have to do is be a marketing major and get a D in the course to understand what exposure like that does to you."
Typically, Pope said, the effect is greatest the year immediately after the athletic success and "decays until you don't see much of an impact 3-4 years later."
That means that the Flutie Effect is long past its expiration date.
"I think it's unlikely [the Flutie Effect is still in effect] given the time lag," Pope wrote. "Today's freshmen were born almost a decade after Flutie's time at BC."
Still, the general principle remains true. For example, just ask Spaziani what made current starting quarterback Chase Rettig want to come to Chestnut Hill.
"One of the things he said was he was home on a Thursday night, watching BC play Virginia Tech and he saw The Pass," Spaziani said, referring to Matt Ryan's game-winning pass to Andre Callender in the 2007 season. "Now that was probably as famous a pass as we've had. It's not the Flutie pass, but it's certainly had a tremendous effect."
Jack McCluskey is an editor for ESPN.com and a frequent contributor to ESPNBoston.com. Follow him on Twitter @jack_mccluskey.