Watch Now: NBA Mock Draft: Obi Toppin Climbing Up To A No. 2 Top Pick (3:20)

On a random Tuesday last May, at some point in the afternoon, Obi Toppin announced he was withdrawing from the 2019 NBA Draft and returning to Dayton. The development got a fraction of the attention that basically any 5-star high school prospect receives when he chooses a college; it didn't even generate a headline on most national websites. But, with the benefit of hindsight, we now know that no decision impacted college basketball this season more than Toppin's decision to withdraw from last year's draft.

There's a lesson in there.

Sure, the most talented college players are usually the heralded freshmen on their way to being one-and-done lottery picks. But what recent history shows is that the top of the sport is often shaped not by those freshmen, but instead by legitimate NBA prospects who decide to return to school.

Obi Toppin is a great example.

So is Devon Dotson.

So is Tre Jones.

Each of those players, after great freshman seasons, could've reasonably entered the 2019 NBA Draft. Jones would've likely been a first-round pick; Toppin and Dotson probably would've been selected in the second round. But all three decided to return to college -- Jones to Duke, Toppin to Dayton, and Dotson to Kansas. And the result of that was Kansas, Dayton and Duke finishing No. 1, No. 4 and No. 5 at KenPom.

Cassius Winston deciding to skip the 2019 NBA Draft and return to Michigan State for his senior year was the key to the Spartans finishing No. 8 at KenPom. Jordan Nwora deciding to skip the 2019 NBA Draft and return to Louisville was the key to the Cardinals finishing No. 9 at KenPom. Jalen Smith deciding to skip the 2019 NBA Draft and return to Maryland was the key to the Terrapins finishing No. 11 at KenPom.

When you add it all up, what you'll find is that six of the top 11 teams in the final KenPom rankings benefitted from legitimate NBA prospects returning to school. That is not a coincidence. In fact, it's a trend.

The best player on each of the past three national-championship teams -- Justin Jackson on 2017 North Carolina, Jalen Brunson on 2018 Villanova and De'Andre Hunter on 2019 Virginia -- was a player who could've reasonably entered the previous year's draft but ultimately decided to do one more year of school. So keep this in mind over the coming days and weeks. Because some massive decisions remain on tap.

Will Filip Petrusev enter the NBA Draft or return to Gonzaga? Will Saddiq Bey stay in the NBA Draft or withdraw and return to Villanova? Will Nate Hinton return to Houston? Will Luka Garza return to Iowa?

And what about the decisions that've already been made?

Will Kentucky losing second-round prospects like Immanuel Quickley and Nick Richards be the thing that prevents the Wildcats from winning next season's national title? Will Ty-Shon Alexander, also a projected second-rounder, leaving Creighton cost the Bluejays a real chance to make their first Final Four in history?

It definitely could.

So, absolutely, you should always pay attention to the recruiting rankings; they matter. But if you're trying to figure out who might be the 2021 national champion, you'd be wise to pay closer attention to the high-end programs with good teams that get legitimate NBA prospects to return for one more year of college basketball because, more often than not lately, that is what has actually been the key to winning it all.