Why is high school recruiting an inexact science? Look no further than this year's rankings of prospects.

Rivals, Scout and ESPNU have finalized their rankings, but can't agree on the top prospect. When someone like John Wall comes along, it's easy. But 2010's different because Scout and ESPNU think North Carolina recruit Harrison Barnes is the best guy out there, while Rivals is going with Kansas recruit Josh Selby.

Oddly enough, Scout and ESPNU both have Selby 5^th. Rivals has Barnes at No. 2, and their Top 10s are essentially the same. Who's right? Who knows? It'll probably be one of those years when everyone misses on a guy like Joakim Noah or Gordon Hayward…

For what it's worth, Gary Parrish likes Barnes at No. 1, mostly because Barnes is "the single most impressive high school kid I've ever met."

Rivals.com's final rankings

1.    Josh Selby (Kansas)

2.    Harrison Barnes (North Carolina)

3.    Enes Kanter (Kentucky)

4.    Kyrie Irving (Duke)

5.    Jared Sullinger (Ohio State)

6.    Brandon Knight (Kentucky)

7.    Tobias Harris (Tennessee)

8.    Cory Joseph (Texas)

9.    Perry Jones (Baylor)

10.  Reggie Bullock (North Carolina)

Scout.com's final rankings

1.    Harrison Barnes (North Carolina)

2.    Kyrie Irving (Duke)

3.    Enes Kanter (Kentucky)

4.    Jared Sullinger (Ohio State)

5.    Josh Selby (Kansas)

6.    Brandon Knight (Kentucky)

7.    Tobias Harris (Tennessee)

8.    Terrence Jones (considering Washington and Kentucky)

9.    Perry Jones (Baylor)

10.  Tristan Thompson (Texas)

ESPNU's final rankings

1.    Harrison Barnes (North Carolina)

2.    Jared Sullinger (Ohio State)

3.    Kyrie Irving (Duke)

4.    Brandon Knight (Kentucky)

5.    Josh Selby (Kansas)

6.    Tobias Harris (Tennessee)

7.    Perry Jones (Baylor)

8.    Will Barton (Memphis)

9.    Terrence Jones (considering Washington and Kentucky)

10.  Tristan Thompson (Texas)

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