[kurosh]

My calculations:
Note - You STOP at the X.
Visual Display: X = hit
10 trials of 10 sequences
X _ _ _ _ _ _ _ _ _ +8
_ X _ _ _ _ _ _ _ _ +7
_ _ X _ _ _ _ _ _ _ +6
_ _ _ X _ _ _ _ _ _ +5
_ _ _ _ X _ _ _ _ _ +4
_ _ _ _ _ X _ _ _ _ +3
_ _ _ _ _ _ X _ _ _ +2
_ _ _ _ _ _ _ X _ _ +1
_ _ _ _ _ _ _ _ X _ 0
_ _ _ _ _ _ _ _ _ X -1
8 + 7 + 6 + 5 + 4 + 3 + 2 + 1 + 0 - 1 = 35
35/10 = 3.5