Always pick a 12 seed to beat a 5 seed

[jacki]

NCAA pool related question, but really a probability question that I don't know how to answer.

All the 'experts' say to always pick a 12 seed to win in the first round every year, but it rings false to me.

There are four 5-12 games.

How often would the 12 need to win to make picking one 12 to win worthwhile -- assuming, of course, you want to be correct more than half the time. What if your goal was to be correct 2/3 of the time?


I'm probably not phrasing this question right, maybe one of you smarty-pants math guys can translate for me /images/graemlins/grin.gif

[2ndGoat]

It is definitely a weird little quirk, but a 12 usually does seem to pull it out.

However, even if a 12 wins every year, you're looking at a 25% chance of picking the right 12, so there's still not much sense trying to chase the right one, unless you really believe a 12 will win for some other reason.

The other thing is you have to consider "how right" you need to be. The larger the pool, the more semi-bizarre picks you have to get right in order to have a shot at the top. This also applies for whether you're picking a frontrunner to win it all or a dark house, where it's less crowded.

2nd

[SumZero]

Right, when you are trying to maximize your chances of winning a pool you do different things than if you are merely trying to maximize your score.

Similar to how you might break a pair to draw to a flush in 5-card draw against several players even though odds are you'd have a better hand against yourself if you kept the pair, but you'll win the pot more if you draw to the flush.

The other thing to consider is if your pool scoring method gives a bonus to upsets. I'm in a pool that gives you a seed differential score if you pick an upset (and the usual 1,2,4,... etc points for each round correct). So if you pick a 5 winning in the first round correctly you get 1 point. If you pick a 12 winning in the first round you get 1 + (12-5) = 8 points. Hence if 3/4 5's win you get 3 points if you choose all 5's but 8 points if you choose all 12's. In this scoring system you almost have to choose all the 9's, 10's, 11's, and 12's in the first round.