Note on probabilities

This probability assumption is simplistic, but the point is that it's simple. Given this assumption, it's fairly easy to come up with the odds that any given seed will win any given round. The following table shows the likelihood that the national champion will be a #1 seed, #2 seed, and so on:

10.743261 in 1.3
20.166721 in 6.0
30.052491 in 19.1
40.019471 in 51.4
50.008551 in 116.9
60.004301 in 232.7
70.002201 in 453.6
80.001131 in 888.8
90.000661 in 1518.3
100.000441 in 2268.1
110.000291 in 3487.4
120.000181 in 5532.6
130.000121 in 8256.3
140.000091 in 11623.4
150.000061 in 17079.8
160.000041 in 26398.0

It is important to note that these are NOT the probabilities that particular teams will win. Rather, the probability shown for #1 seeds is the probability that one of the four of them will end up as national champion. (And similarly for the other seeds.) Since there are four teams with each seed in the tournament (and since each follows a theoretically similar path to the title), the likelihood for a specific team to win it all is really 1/4 of the value shown in the table.

The upshot of all this commentary is to guess how many trials the script will run if you tell it to force a particular team as the winner. For example, suppose your team is seeded 3rd. Since each 3rd seed has a 1 in 19.1 chance of winning it all, it will take the script, on average, about 4x19 = 76 trials to come up with your team as the winner. In practice, randomness being what it is, it could take anywhere from 1 trial up to a skillion or more.