I recently had the pockets on my Gold Crown II shrunk down from 5" to about 4.5". The ghost now wins an average of 1 to 2 more racks against me in a race to 7 than it did before the change. Based on that, I would guess that a player who beats the ghost (whichever ghost they play) 50% of the time on 5" pockets may see their winning percentage drop to below 40% on 4.5" pockets, since many balls that "barely fell" will become balls that "nearly fell".
Aaron
Aaron