Scoring Rules (2012)
From Bot Brackets Wiki
This is an explanation of why the particular scoring rules for 2012 have been adopted. The problems we had with last year were:
- In Jeremy's bracket contest, there is an inherent balance between getting a lot of points for an upset and, if you're wrong, getting 0 points for subsequent games. In this contest, by design you can't be completely out of a game, so this heavily skews results in favor of picking upsets. Note that that was the winning strategy for both the #1 and #2 entries last year.
- In the occasional scenario where a low seed makes it to the final four (like #8 Butler in 2011 or both #5 Butler and #5 Michigan State in 2010), it's worth a disproportionate number of points. You can see this effect by the spike in the average points per game for round 4 below.
- The contest is pretty much over before the final four games, especially since dropping the seed multiplier makes the game really low scoring.
To fix this, the rules will be changed as follows:
- The value of the seed drops over time, so the Seed term is now essentially
Seed / (Round+1)
. (The actual expression is more likefloor(1+(Seed-1)/(Round+1))
.) A #8 in round 4 would only be worth 2, and a #5 is only worth 1. - To increase the effect of subsequent rounds, the Round term has been changed from 5, 10, 15, ..., to 5, 15, 25, ..., which is expressed as
(10*Round - 5)
.
Using the past few years as data points, you get the following distributions:
2011 Rules: 5 * Round * (Round <= 4 ? Seed : 1)
|
2012 Rules: (10 * Round - 5) * (Seed / (Round+1))
|
---|---|
How That Would Change Results
By applying those rules to last year's contest, the new results would be:
User | Bot Name | New Score | Change In Rank |
---|---|---|---|
Michael O'Halloran | There's No Need to Fear | 1105.000 | same |
Darrel Hutchins | Fibs, Lies, and Statistics | 920.318 | +2 |
Darrel Hutchins | Big Stuff | 914.974 | same |
Brent Cox | PastPerformance | 908.409 | +3 |
Stock | Low Seed Wins | 895.000 | -3 |
Michael O'Halloran | Bot-tastic | 868.206 | +3 |
Stock | Coin Flip | 862.500 | -1 |
Rick Bassham | Random | 861.616 | -3 |
Stock | High Seed Wins | 830.000 | +4 |
Daniel Reid | Random | 823.781 | +2 |
Stock | Split the Middle | 773.535 | same |
Darrel Hutchins | Déjà Vu | 767.500 | -2 |
Daniel Reid | Contrarian | 765.000 | +1 |
David Jones | Human Bracket | 739.000 | -2 |
David Jones | High Seed Mostly Wins | 738.869 | same |
David Jones | Using Statistics | 735.276 | same |
Brent Cox | SOLOOLT | 725.000 | +1 |
Brent Cox | Haven'tISeenYouBefore? | 722.417 | -1 |
Daniel Reid | Contrarian 2 | 675.000 | same |
Michael O'Halloran | Modified RPI | 670.000 | same |
This shows "There's No Need To Fear" clearly dominating the competition. The last round is only worth 55 points, so it would have been over by then. The idea that a "low seed wins" variant can do so well is still troubling. I do like how much closer the rest of the field looks, though.