[Odinn]

At their best days(ordered by alphabetically);
Kareem Abdul-Jabbar
Wilt Chamberlain
Tim Duncan
Patrick Ewing
Dikembe Mutombo
Hakeem Olajuwon
David Robinson
Dennis Rodman
Bill Russell
Nate Thurmond
Ben Wallace
Bill Walton

The closest guard to make an impact of big man; Walt Frazier.