Exactly how we define the power forward position keeps changing by the year. Is it enough to merely rebound at the position and defend fellow fours? Does a power forward need to be a rim protector? Is a power forward just a name for another wing at this point, the designation going to whichever of the two is taller? The answer to all of these questions is both yes and no, reflecting an NBA, and by extension a college game, truly in transition. So not all these players look or play the same. Some might end up as threes, others as fives. This is my best guess at the top 20 I think will play the four when they get to NBA camps.

1. Jayson Tatum, Duke

Tatum represents every bit of the next-generation NBA four, between the comfort handling the ball, rim protection, the impressive floor-stretching shot and solid rebounding. He can play the three, but he’ll do the most damage at the four.

2. Lauri Markkanen, Arizona

The three-point range is unquestionable. What isn’t yet clear is whether he’ll be quick enough to guard fours, thus allowing his team to create the mismatches he should force routinely.

3. Johnathan Motley, Baylor

A late bloomer who can score with either hand, with a deft passing touch overtaking shot-blocking in his profile as he’s matured.

4. John Collins, Wake Forest

The nation’s leader in Player Efficiency Rating, capable of scoring explosions, grabbing more than 25 percent of available defensive rebounds, with an NBA-ready frame now.

5. T.J. Leaf, UCLA

Taking every advantage of the remarkable passing by Lonzo Ball, with a developed midrange and even post game.

6. Caleb Swanigan, Purdue

There’s been no more effective big man this year in the college game than Swanigan, from vacuuming rebounds to efficient threes.

7. Alec Peters, Valparaiso

A Horizon League monster with a power-five conference body and well-developed postgame.

8. Kris Jenkins, Villanova

Elite defender who makes threes and is tough enough to body up against opposing fours right now, with big-shot capabilities you may remember.

9. Ethan Happ, Wisconsin

Ah, he can do everything on a basketball court except shoot.

10. Angel Delgado, Seton Hall

One of the nation’s best rebounders, Delgado has improved his post game significantly this season. Needs to get better at defending opposing bigs, or find range out to three, to really stick.

11. Nigel Hayes, Wisconsin

Smart, tough, and a plus passer for his size.

12. Gary Clark, Cincinnati

The ultimate Mick Cronin player, Clark can help an NBA rotation with both his toughness on the defensive end and ability to rebound over taller players.

13. Chris Boucher, Oregon

The shooting has stagnated, even regressed, but Boucher can rim protect with the best of the fours.

14. Cameron Oliver, Nevada

Still raw, but making nearly 39 percent of his threes, and what an amazing athlete.

15. Eric Mika, BYU

Woke up the world to his routine double-doubles against Gonzaga, but he’s been doing that all year.

16. Kyle Kuzma, Utah

Quietly keeps on stretching out his range, year by year, which he’ll need as someone with NBA length but not yet an NBA body to bang with fours.

17. Luke Kornet, Vanderbilt

I’ve loved Kornet’s shot mechanics and bloodlines for a long time, and the stats are finally starting to back that up, with 35.4 percent accuracy on threes. Better shot selection is one key for him this season. Needs to stick at the four, given defensive limitations.

18. Isaiah Hicks, North Carolina

NBA body now, and I’m convinced his rebounding numbers are artificially depressed by playing next to Kennedy Meeks.

19. William Lee, UAB

A legit 6’9 with 38.3 percent accuracy from three and a stroke that suggests he’ll get even better. Strong defensive rebounder and passer, too. Lost in the Conference USA murky middle, but shouldn’t be.

20. Mike Watkins, Penn State

Has the NBA build as a freshman, and the results are clear: he’s grabbing 26.9 percent of available defensive rebounders. If he gets no better, grades out as a potential Reggie Evans already.