Editor's note: This is the latest part of a four-day, seven-piece series on college basketball's biggest change agents in the past 20 years and what the future will bring.
LeBron James, Kobe Bryant, Kevin Garnett and Amare Stoudemire almost certainly would have been superstars in their first (and perhaps only) seasons in college.
We feel pretty comfortable with that claim.
On the other hand, while we know Shaun Livingston would have made a difference at Duke and we're fairly certain J.R. Smith would have given North Carolina even more outside shooting last season, would either team's season have turned out that much differently?
Would Smith, who might have been the seventh man behind Marvin Williams, have made a difference, since the Tar Heels won the national title without him? Duke could have used Livingston, but it's not a given the Blue Devils would have gone much farther than the Sweet 16 with him last March.
And that's the point. If we're talking about preps-to-pros who would have been college superstars, having Carmelo Anthony-type impact, we have to limit it to the aforementioned foursome.
Sure, there's an argument for others who skipped the experience that occupies the time between high school and the NBA. You can make a case for the potential impact of Sebastian Telfair at Louisville, Eddy Curry at DePaul, Robert Swift at USC, Kwame Brown at Florida, Josh Smith at Indiana, Al Jefferson at Arkansas, DeShawn Stevenson at Kansas, Darius Miles at St. John's, Jonathan Bender and Travis Outlaw at Mississippi State, Kendrick Perkins at Memphis, Dorrell Wright at DePaul, Ndudi Ebi at Arizona and Dwight Howard and Tyson Chandler, destinations unknown.
Still, none of them were locks to be dominant. Which means the new NBA draft rule for high school seniors, which states an early-entry must be 19 and one year out of high school, might not have the dramatic impact on college basketball that many expect.
"What we learned is that a kid that didn't make it [to the NBA] straight out probably wasn't going to make it [big in the pros] anyway,'' Memphis coach John Calipari said.
More damaging will be the continued early-entry departures of players who don't make it to year two, three or four in their programs. It's not the kids who never show up -- what really hurts is the kids who do play well and then leave early.
"The new rule is going to allow them to start plucking more of our guys out of our program,'' Florida coach Billy Donovan said. "Now there will be guys in your program who never considered going [early who] will go because there will be spots in the draft. The cycle will be more vicious than ever.''
That still doesn't mean coaches don't think about what might have been.
Donovan lost Brown, the No. 1 overall pick in 2001. But Brown struggled mightily his first year in the NBA (and still hasn't developed into the star he was expected to be). Can we make the assumption that he would have struggled the same way in college had he played for Florida, even for one year?
Apparently not, according to Donovan.
"He was the first player in the draft, so he was going to have some type of impact,'' Donovan said of his Gators that that finished 22-9, 10-6 in the SEC East and lost in the NCAA first round in 2001-02.
"I'm not saying he would have been first-team all league but he certainly would have gone with Udonis Haslem, David Lee, James White and Matt Bonner,'' Donovan said. "High school is closer to the college game and he was in the NBA where he had money, was traveling and played 82 games. It was a totally different world and rules.''
Calipari and Mississippi State coach Rick Stansbury, two coaches who have been burned as much as any in the country by signing players only to lose them to the NBA, say the one season with players like Perkins and Bender (who essentially have become NBA role players) would have been significant. Forget about stardom, it's the extra contributions to the core that they missed big-time.
"What would my team have been like? We had no big guy, so if Perkins had come with us, we would have gone to the Sweet 16 or Elite Eight instead of the second round,'' Calipari said of the Tigers' NCAA appearance two years ago (when they beat South Carolina and lost to Oklahoma State).
"There is a domino effect,'' Calipari said. "What if Luol Deng had stayed [for his second year] and Livingston commits [to play as a freshman]? Then maybe Duke wins every game. What if J.R. Smith accepts the seventh spot behind Williams? Then would North Carolina have lost a game? If the kid is going to go to the NBA, then he probably could help your team, unless he was a jerk.''
True. But we want to know if any of these players would have really made a major -- and we mean title-like, Final Four-like -- difference if they had come to college for one season.
Stansbury knows the frustration. He is missing out on Monta Ellis (who would have been the scoring guard the Bulldogs lack) this season and has the perspective from almost annual losses to the NBA draft.
"The Bender year was probably the most impact we've felt of any of them because we were depending on him that year,'' Stansbury said. "We've gone to the postseason six out of seven years [four NCAAs and two NITs] and that's the one year  we didn't after we lost him [to the NBA].''
The Bulldogs signed Outlaw in 2003 and went 26-4 and won the SEC championship the next season. Yes, the Bulldogs were fortunate to pick up Lawrence Roberts in August after the Baylor scandal, but Outlaw's loss still was felt -- even if he wouldn't have been a true impact player as a freshman.
"He wouldn't have started ahead of Brandon Vincent,'' Stansbury said. "I agree that none are in the class of [Kobe, Garnett, LeBron and Amare], but some of these guys would have made their teams better. What you don't know is if you got them for that second year. Now, all of a sudden, you would have an impact player. Most wouldn't have an impact that first year, but if you get them the second year then they could have a major impact on the game.
"If you're only talking about one year and out, then they wouldn't have that kind of impact,'' Stansbury said.
That's exactly what we mean. If the players who bolted to the NBA straight out of high school would have gone pro after one season anyway, the impact on the college game wouldn't have been that significant.
Come to think of it, the college game seems to have been fine without most of these players, save Garnett, Kobe, LeBron and Amare. Those four could have had Ewing-like careers or even a magical Anthony one-and-done season. Most of the rest have come through in other forms and been replaced without their being sorely missed.
Andy Katz is a senior writer at ESPN.com.