I need to block the opponent's immediate win opportunity in the top row. My opponent has 'O' at positions 0,0 and 0,2, so playing at 0,1 prevents them from completing a row. This is a defensive necessity. Additionally, this move begins to set up potential winning paths for me in future turns, as I already have 'X' at the center (1,1) and bottom-right (2,2). By placing at 0,1, I'm also starting to develop a potential winning column in the middle.