For character creation my group sometimes uses a weird method to generate stats. We roll 6 stat arrays using 4d6d1 (rolling 4d6 and dropping the lowest), and arrange them on top of one another to make a 6x6 matrix. We can then choose any row, column, or diagonal as our stat array.
An example of a matrix generated this way:
Giving us the following options for our stat array (Row 3 seems to be the best in this case):
LR and RL are the diagonals from the Top Left to the Bottom Right, and Top Right to the Bottom Left respectively.
What is the average point buy of using this method? And how is it calculated in this case?