Pretty cool -- two players face off and you vote who's the better player. The system then adds or subtracts points to their Elo Rating, a system designed to prove who's the better player using a system for rating chess players.
The current Top 10s:
Current Top Ten (Batters):
1. Babe Ruth (2527)
2. Ted Williams (2516)
3. Ty Cobb (2511)
4. Stan Musial (2505)
5. Mickey Mantle (2501)
6. Rogers Hornsby (2498)
7. Albert Pujols (2489)
8. Honus Wagner (2484)
9. Hank Aaron (2484)
10. Rickey Henderson (2471)
Current Top Ten (Pitchers):
1. Tom Seaver (2326)
2. Greg Maddux (2307)
3. Lefty Grove (2298)
4. Cy Young (2297)
5. Walter Johnson (2297)
6. Christy Mathewson (2285)
7. Roger Clemens (2284)
8. Bob Gibson (2275)
9. Phil Niekro (2271)
10. Steve Carlton (2267)
The current Top 10s:
Current Top Ten (Batters):
1. Babe Ruth (2527)
2. Ted Williams (2516)
3. Ty Cobb (2511)
4. Stan Musial (2505)
5. Mickey Mantle (2501)
6. Rogers Hornsby (2498)
7. Albert Pujols (2489)
8. Honus Wagner (2484)
9. Hank Aaron (2484)
10. Rickey Henderson (2471)
Current Top Ten (Pitchers):
1. Tom Seaver (2326)
2. Greg Maddux (2307)
3. Lefty Grove (2298)
4. Cy Young (2297)
5. Walter Johnson (2297)
6. Christy Mathewson (2285)
7. Roger Clemens (2284)
8. Bob Gibson (2275)
9. Phil Niekro (2271)
10. Steve Carlton (2267)