[BEST OF MLS] Most teams in MLS use a four-man back line as their base defensive formation, and that is how we list them in our annual positional rankings; left backs, central defenders, and right backs. The same designations are used, somewhat arbitrarily, to include players often deployed in a three-man back line, as in the case of D.C. United.

Players who missed league matches due to injuries, suspensions, or international callups are downgraded, as only performances in 2009 league matches are evaluated for this listing. For example, Chad Marshall of Columbus repeated as MLS Defender of the Year, but he played only 18 games, and teammate Frankie Hejduk played just 14 games).

Here are the rankings for 2009:

LEFT BACKS
1. Jonathan Bornstein (Chivas USA)
2. Todd Dunivant (Los Angeles)
3. Gino Padula (Columbus)
4. Chris Wingert (Real Salt Lake)
5. Jim Brennan (Toronto FC)
6. Mark Burch (D.C. United)
7. Gonzalo Segares (Chicago)
8. Jay Heaps (New England)
9. Jair Benitez (FC Dallas)
10. Leo Gonzalez (Seattle)

CENTRAL DEFENDERS
1. Geoff Cameron (Houston)
2. Eduardo Hurtado (Seattle FC)
3. Nat Borchers (Real Salt Lake)
4. Chad Marshall (Columbus)
5. Gregg Berhalter (Los Angeles)
6. Omar Gonzalez (Los Angeles)
7. Wilman Conde (Chicago)
8. Jimmy Conrad (Kansas City)
9. Dejan Jakovic (D.C. United)
10. Carey Talley (Chivas USA)
11. Jamison Olave (Real Salt Lake)
12. Bobby Boswell (Houston)
13. Emmanuel Osei (New England )
14. Tyrone Marshall (Seattle)
15. Jason Hernandez (San Jose)

RIGHT BACKS
1. Bryan Namoff (D.C. United)
2. Kevin Alston (New England)
3. Chris Leitch (San Jose)
4. A.J. DeLaGarza (Los Angeles)
5. Frankie Hejduk (Columbus)
6. Marvell Wynne (Toronto FC)
7. James Riley (Seattle)
8. Tim Ward (Chicago)
9. Mariano Trujillo (Chivas USA)
10. Jeremy Hall (New York)