Depth Limit

Hi All,

I am using a minimax algorithm with alpha beta cutoff to play othello

I was trying to get my software to challange itself by having two
players with
the same implementation to compete.

One of the players was searching up to a depth of 5 and the other
player was
searching up to depth of 9-10.

Suprisingly the 5 depth player wins big time. Could it be a bug or is
there essential thing I am missing (e.g Limit depth in the inital
stages of the game)

It is making sense that the Game tree will change since the other
player is not optimal.

Please advice.

Thanks .