Tässä vähän tämmöstä pikaista testiä! :)

choice_game.py

 from itertools import chain
import random

def shift(cards, shift):
    return [ cards[(i - shift) % len(cards)] for i in range(0, len(cards) ) ]

def shuffle(cards, m):
    return [ [ card for pos, card in enumerate(chain(*cards)) if pos % m == p ] for p in range(0, m) ]

def shift_amt(position, m, n):
    return (m // 2 - position) % m

def selection_trick(m, n):
    cards = list(partition( range(0, n*m), n ))
    selection = random.randint(0, m*n - 1)

    for i in range(0, m):
        position = [ p for p, cds in enumerate(cards) for card in cds if card == selection ][0]
        cards = shuffle( shift(cards, shift_amt( position, m, n )), m)

    result = list(chain(*cards))[ m*n // 2]
    return selection == result

if __name__ == '__main__':
    print [ (m, n) for m in range(1, 10) for n in range(1, 10) if selection_trick(m, n) ]