Who was the best defensive player in NBA history?

Probably Bill Russell. The man was so intimidating on defense that opposing teams would settle for low percentage shots farther and farther from the basket because they knew Russell was waiting in the interior waiting to block any shots near the rim. The guy would have averaged 10+ blocks a game had they been counted back then and numerous DPOY awards..

BTW if anyone is interested I can give a list of the best defensive players by position this is how I would rank them:

PG:

  1. Gary Payton
  2. Walt Frazier
  3. Dennis Johnson
  4. Norm Van Lier
  5. Mookie Blaylock
  6. Don Buse
  7. Maurice Cheeks
  8. Jason Kidd
  9. Chris Paul
  10. John Stockton

SG:

  1. Michael Jordan
  2. Sidney Moncrief
  3. Michael Cooper
  4. Alvin Robertson
  5. Joe Dumars
  6. Jerry Sloan
  7. Tony Allen
  8. Jerry West
  9. Kobe Bryant
  10. Eddie Jones

SF:

  1. Scottie Pippen
  2. Kawhi Leonard
  3. John Havlicek
  4. Metta World Peace
  5. Bruce Bowen
  6. Lebron James
  7. Tayshaun Prince
  8. Paul George
  9. Larry Nance
  10. Andre Iguodala

PF:

  1. Dennis Rodman
  2. Kevin Garnett
  3. Tim Duncan
  4. Bobby Jones
  5. Kevin McHale
  6. Dave Debusschere
  7. Dan Roundfield
  8. Draymond Green
  9. Giannis Antetokounmpo
  10. Paul Silas

C:

  1. Bill Russell
  2. Wilt Chamberlain
  3. Nate Thurmond
  4. Hakeem Olajuwon
  5. Dikembe Mutombo
  6. Ben Wallace
  7. David Robinson
  8. Dwight Howard
  9. Alonzo Mourning
  10. Mark Eaton (but it’s close between him, Alonzo Mourning and Artis Gilmore)