3 ms·
Actually, assuming "a number of fingers" is in the range 1..10, thats only fair for 2, 5, or 10 players (or maybe some >10) (if it's 0..10, I think it only work
by a1369209993 7y ago
Actually, assuming "a number of fingers" is in the range 1..10, thats only fair for 2, 5, or 10 players (or maybe some >10) (if it's 0..10, I think it only works for exactly 11 players).
In the case of 3 players you get random numbers (reduced modulo 3): 1,4,7,10 => 1 40% of the time; 2,5,8 => 2 30%; 3,6,9 => 3 30%
Two random numbers produce: 1 @ 33%; 2 @ 30%; 3 @ 37%
And after adding the third number you get: 1 @ 30.9%; 2 @ 34.9%; 3 @ 34.2%
(These percentages are all exact BTW.)
So this is biased against player 1 (which is not actually the way I was expecting it to go). And if you want to cheat, you should assume the other players will add up to 3, and pick a number accordingly.
I assume 4,6,7,8,9 out of ten and anything out of 11 work similarly, but I haven't checked the numbers.
If "a number of fingers" is 1..N (or 0..^N) then it's unbiased, but just doesn't work at all for >10 (or >11 respectively).
- User23 7y agoI'd never considered it in this light, but drawing straws really does have some pleasant properties.