Not all random numbers are created equal
October 25, 2009 11:30 PM Subscribe
How do I get a controlled distribution of random numbers to fairly determine a start position.
posted by monkeystronghold to education (21 answers total)
In a sporting event, start position is decided based on the last digit of your registration number. Each week, random numbers are drawn to decide the start order. For example, the random draw order for a single week is 4, 0, 3, 5, 1, 8, 7, 9, 6, 2. So everyone with a number ending in 4 starts first. Everyone with a number ending in 0 starts second. And so on. The next week the draw order is again random.
While this works, the distribution of of numbers can end up being unfair (one particular number can be "lucky" or "unlucky" for many weeks). Statistically, how would one generate a set of "random" start orders so that the value of each registration number was roughly equal over the course of a season (for ease of calculation, let's say 10 weeks).
I don't know anything about math or statistics, so my description of this situation probably uses lots of words incorrectly. I'd google this, but I don't even know how to start.
Basically, is it possible for value of all of the numbers to even out. But in a random order. So, for example, that 0's aren't always going after 4's. And one group doesn't always start in the middle.