Tasting tea

import itertools as it

selects = list(it.combinations(range(8), 4))

len(selects)

70

# Chance picking at random, uniform probability.
100.0 * (1.0 / 70.0)

1.4285714285714286

import numpy as np

npselects = np.array(selects)

np.sum((npselects < 4).astype(int), axis=1)

array([4, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2,
       2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 3, 3, 3, 3, 2, 2, 2, 2, 2,
       2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1,
       1, 1, 1, 0])