Following on from my last post. If he waits for 2 small bets where the first wins and the 2nd loses, then bets big, then shifting by 1 will result in the big bet losing, while shifting by 2 will result in it winning.
Pretty nice result. You guys found his betting pattern by shifting. shift 1: mostly loss, shift 2: mostly win... hence pattern is: wait for "WL", then bet high.