There are a lot of ways to do that. I would generate 3D array, where the third dimension will be of the size = # of rounds (5);
So you will have array X(m,n,r), where r=1:5 (if number of rounds is 5).
Now, use mean and stddiv with second argument 3:
MeanX=mean(X,3); StddivX=stddiv(X,3);
This will calculate mean and stddiv through 3rd dimension. As a result you obtain two 2D arrays, what you were asking.
