Generating natural schedule for a sports league

Question

I\'m looking for an algorithm to generate a schedule for a set of teams. For example, imagine a sports season in which each team plays each other, one time as home team and

Answer 1

I found a method here which I adapted slightly to this:

def round_robin(units, sets = None):
    """ Generates a schedule of "fair" pairings from a list of units """
    count = len(units)
    sets = sets or (count - 1)
    half = count / 2
    for turn in range(sets):
        left = units[:half]
        right = units[count - half - 1 + 1:][::-1]
        pairings = zip(left, right)
        if turn % 2 == 1:
            pairings = [(y, x) for (x, y) in pairings]
        units.insert(1, units.pop())
        yield pairings

teams = ['a', 'b', 'c', 'd']
print list(round_robin(teams, sets = len(teams) * 2 - 2))

Now I just need to turn this into plpgsql. :)