Looking at the current board:
```
 O | X | X
 -----------
 X | X | O
 -----------
 . | O | .
```

I need to consider both offensive and defensive strategies:

1. Neither position (2,0) nor (2,2) gives me an immediate win.

2. Defensive analysis: If I place O at (2,2) and my opponent places X at (2,0) next, they would have X at positions (0,2), (1,1), and (2,0) - creating a diagonal win from top-right to bottom-left.

3. By playing at position (2,0), I block this potential diagonal win.

4. This move also sets up a potential win for me in the bottom row with Os at positions (2,0) and (2,1), though my opponent would likely block at (2,2) in their next move.

Position (2,0) is the optimal defensive move that prevents my opponent from winning on their next turn.