Saturday, December 26, 2009

From the self-deprecation department

This year was the first year that I followed our web traffic at any level of detail. The normal pattern has been that traffic spikes on Sundays during the regular season. But that traffic has dropped off dramatically following the big spike on BCS Selection Sunday. Right now, maybe that looks like a positive development (smile) seeing how poorly we're doing so far in our now annual use of the RWFL rankings to try to pick the bowl games. This year's RWFL-based selections have correctly picked 1 of the 6 bowl games so far this season, putting us currently at the 9.9th percentile in ESPN's College Bowl Mania. That's right, more than 90% of entries are currently performing better than our picks. Impressive! But there are a lot of games left to play, so we'll see how it shakes out in the long run. After all, our entry can't drop much lower.

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Saturday, December 19, 2009

Last Minute Bowl Game Preparations

The first bowl games are only hours away, so it's time to get ready! No, I don't mean chili and guacamole (though that sounds good). I mean our third annual attempt to use the rankings to predict the bowl games. We'll once again be playing over at ESPN's College Bowl Mania (not endorsing it, it's just where I'm signed up), which requires predictions of outcomes and rank-ordering of confidence in those predictions. The 2007 random walker bowl predictions turned out pretty well, placing above the 75th percentile of all entries, which I believe is good for a fully automated system. The 2008 bowl predictions, however, really missed the mark. But that doesn't stop us from coming back to try again.

The big caveats up front are that we definitely do not recommend these rankings for anything beyond entertainment. The underlying rankings are not intended to be best in any sense, except that they are relatively simple to explain. And the methodology used to assign predictive probabilities here is fundamentally flawed. The general principle we use is that we assign a probability to a victory by the higher-ranked team such that the addition of a mythical fractional-outcome game split according to those probabilities does not change the existing rankings. However, this simple principle is fabulously erroneous for many reasons, not the least of which is that it can algebraically return a greater-than-100% chance of victory. You might think a mathematician would bother to fix such a problem, but there are so many other flaws in trying to use these rankings to predict upcoming games that it's unclear whether further detailed work would yield anything useful.

Like past years, we used the full-component RWFL predictions at p=0.75 (see other parts of this site for those details). Each game selection is specified by predicting the higher-ranked team will beat the lower-ranked team. The games are presented in order of confidence (highest to lowest), determined by the mean of the stated probability spread (obtained individually by the first-place votes and the last-place votes). I'm happy to discuss such details further, though I warn again that it is a relatively crude model. And since I'm assuming visitors just want the results, let's get to the predictions.

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International
South Florida (7-5) over Northern Illinois (7-5)
70-82%
----
AdvoCare V100 Independence
Georgia (7-5) over Texas A&M (6-6)
67-79%
----
Chick-fil-A
Virginia Tech (9-3) over Tennessee (7-5)
69-76%
----
Emerald
Southern Cal (8-4) over Boston College (8-4)
65-70%
----
Rose Bowl Game presented by Citi
Oregon (10-2) over Ohio State (10-2)
61-71%
----
Brut Sun
Stanford (8-4) over Oklahoma (7-5)
63-69%
----
Insight
Minnesota (6-6) over Iowa St (6-6)
65-67%
----
Konica Minolta Gator
West Virginia (9-3) over Florida St (6-6)
65-67%
----
New Mexico
Fresno St (8-4) over Wyoming (6-6)
65-66%
----
Pacific Life Holiday
Arizona (8-4) over Nebraska (9-4)
65-66%
----
EagleBank
UCLA (6-6) over Temple (9-3)
56-70%
----
Outback
Auburn (7-5) over Northwestern (8-4)
61-62%
----
Papajohns.com
South Carolina (7-5) over Connecticut (7-5)
61-62%
----
Valero Alamo
Texas Tech (8-4) over Michigan St (6-6)
57-66%
----
Champs Sports
Miami FL (9-3) over Wisconsin (9-3)
56-67%
----
Sheraton Hawaii
Nevada (8-4) over SMU (7-5)
56-65%
----
Bell Helicopter Armed Forces
Houston (10-3) over Air Force (7-5)
47-75%
----
FedEx Orange
Georgia Tech (11-2) over Iowa (10-2)
56-61%
----
Citi BCS National Championship Game
Alabama (13-0) over Texas (13-0)
47-70%
----
Texas
Missouri (8-4) over Navy (8-4)
54-60%
----
Gaylord Hotels Music City
Clemson (8-5) over Kentucky (7-5)
57-58%
----
St. Petersburg
Central Florida (8-4) over Rutgers (8-4)
50-65%
----
R+L Carriers New Orleans
Middle Tennessee St (9-3) over Southern Miss (7-5)
56-57%
----
S.D. County Credit Union Poinsettia
California (8-4) over Utah (9-3)
53-59%
----
AT&T Cotton
Oklahoma St (9-3) over Mississippi (8-4)
52-59%
----
Allstate Sugar
Florida (12-1) over Cincinnati (12-0)
52-59%
----
Capital One
LSU (9-3) over Penn State (10-2)
50-60%
----
Tostitos Fiesta
TCU (12-0) over Boise St (13-0)
53-55%
----
Roady's Humanitarian
Idaho (7-5) over Bowling Green (7-5)
50-58%
----
GMAC
Central Michigan (11-2) over Troy (9-3)
54-54%
----
Little Caesars
Ohio U. (9-4) over Marshall (6-6)
52-53%
----
AutoZone Liberty
Arkansas (7-5) over East Carolina (9-4)
44-55%
----
MAACO Las Vegas
Oregon St (8-4) over Brigham Young (10-2)
49-50%
----
Meineke Car Care
North Carolina (8-4) over Pittsburgh (9-3)
39-51%
----

Note, in particular, the toss-up nature in the last picks above. Meanwhile, even some of the more confident calls include probability spreads that dip below 50%, including the call for the BCS National Championship Game.

By the way, we get a LOT more visitors than comments on this site. Feel free to express your opinion about the accuracy (or better yet, the stupidity) of these predictions!

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Sunday, December 6, 2009

Rankings through December 5th

Every time you changed the channel yesterday, there was another wild game on. Alabama rolled Florida. Texas survived last-second confusion and won on a last-second FG. Cincy came back from 21 down and won by the difference of Pitt's botched extra point attempt following a perhaps too-early TD. GT won a back-and-forth match with Clemson. And Fresno State beat Illinois on a stretch into the endzone in the last seconds, followed by a fluke tip drill two-point conversion. Okay, so that last one has zero implication for the BCS bowls, and most of us probably only saw it on SportsCenter; but it was crazy.

Cincy and TCU fans are probably steaming this morning that Texas got that second back. And Texas will probably lose a few votes in the BCS Standings, but the conventional wisdom seems to be that their lead over TCU last week was so large that it won't matter: Texas will play Alabama for the championship.

TCU will get the non-AQ group automatic qualification. The three remaining BCS at-large bids are up to the bowls themselves, but it seems certain that Florida will get one, and it seems likely that Boise State and either Iowa or Penn State will get the other. That is, unless a bowl game chooses to go to a three-loss team, it's just a matter of which team goes where; Brad Edwards at ESPN concisely breaks the process down and makes predictions.

Finally, on to our own rankings. Note the figure below the rank ordering of the 120 teams, because it says something interesting this week. Specifically, it plots the order of the top teams under varying the single "p value" bias parameter in our ranking system, which is a highly imperfect proxy for exploring other ranking systems that work under the same limiting assumptions (notably no margin of victory and no information about dates of games). While Alabama remains the undisputed #1 as the bias varies between its allowed values, Cincy, Florida, and Texas each make appearances at #2.

2009 Random Walker Rankings (RWFL, p=0.75)
Games through Saturday December 5th:
1. Alabama (13-0) [1.6882]
2. Florida (12-1) [1.2422]
3. Cincinnati (12-0) [1.2000]
4. Texas (13-0) [1.1248]
5. TCU (12-0) [1.0198]
6. Oregon (10-2) [1.0023]
7. Georgia Tech (11-2) [0.9651]
8. Boise St (13-0) [0.9495]
9. Virginia Tech (9-3) [0.8073]
10. Ohio State (10-2) [0.7910]
11. LSU (9-3) [0.7865]
12. Iowa (10-2) [0.7746]
13. Miami FL (9-3) [0.7666]
14. West Virginia (9-3) [0.6841]
15. Arizona (8-4) [0.6710]
16. Southern Cal (8-4) [0.6678]
17. Stanford (8-4) [0.6546]
18. North Carolina (8-4) [0.6454]
19. Penn State (10-2) [0.6447]
20. Pittsburgh (9-3) [0.6344]
21. Oregon St (8-4) [0.6244]
22. Brigham Young (10-2) [0.6235]
23. Georgia (7-5) [0.6216]
24. Oklahoma St (9-3) [0.6175]
25. California (8-4) [0.6021]
26. Mississippi (8-4) [0.5896]
27. South Carolina (7-5) [0.5764]
28. Clemson (8-5) [0.5750]
29. Arkansas (7-5) [0.5734]
30. Auburn (7-5) [0.5696]
31. Tennessee (7-5) [0.5425]
32. Wisconsin (9-3) [0.5406]
33. Houston (10-3) [0.5280]
34. East Carolina (9-4) [0.5162]
35. Kentucky (7-5) [0.4978]
36. Utah (9-3) [0.4977]
37. Nebraska (9-4) [0.4903]
38. Boston College (8-4) [0.4878]
39. Florida St (6-6) [0.4825]
40. Texas Tech (8-4) [0.4599]
41. Missouri (8-4) [0.4591]
42. Central Michigan (11-2) [0.4558]
43. Northwestern (8-4) [0.4454]
44. Connecticut (7-5) [0.4429]
45. Oklahoma (7-5) [0.4380]
46. Washington (5-7) [0.4369]
47. South Florida (7-5) [0.4368]
48. Mississippi St (5-7) [0.4327]
49. Troy (9-3) [0.4211]
50. Central Florida (8-4) [0.4205]
51. Fresno St (8-4) [0.4197]
52. UCLA (6-6) [0.4193]
53. Rutgers (8-4) [0.4184]
54. Navy (8-4) [0.4175]
55. Nevada (8-4) [0.4011]
56. Notre Dame (6-6) [0.3973]
57. Minnesota (6-6) [0.3862]
58. Temple (9-3) [0.3607]
59. SMU (7-5) [0.3477]
60. Middle Tennessee St (9-3) [0.3437]
61. Wake Forest (5-7) [0.3422]
62. Michigan St (6-6) [0.3296]
63. Texas A&M (6-6) [0.3279]
64. Ohio U. (9-4) [0.3254]
65. Air Force (7-5) [0.3141]
66. North Carolina St (5-7) [0.3131]
67. Purdue (5-7) [0.3102]
68. Marshall (6-6) [0.3034]
69. Wyoming (6-6) [0.3017]
70. Idaho (7-5) [0.3011]
71. Southern Miss (7-5) [0.2985]
72. Bowling Green (7-5) [0.2968]
73. Arizona St (4-8) [0.2795]
74. Iowa St (6-6) [0.2771]
75. Virginia (3-9) [0.2765]
76. Syracuse (4-8) [0.2763]
77. Kansas St (6-6) [0.2736]
78. Duke (5-7) [0.2680]
79. Kansas (5-7) [0.2590]
80. UNLV (5-7) [0.2453]
81. Hawai`i (6-7) [0.2430]
82. Baylor (4-8) [0.2417]
83. Louisville (4-8) [0.2379]
84. Michigan (5-7) [0.2319]
85. Alabama-Birmingham (5-7) [0.2182]
86. Illinois (3-9) [0.2168]
87. Louisiana-Monroe (6-6) [0.2137]
88. Colorado (3-9) [0.2120]
89. Northern Illinois (7-5) [0.2065]
90. Louisiana-Lafayette (6-6) [0.2039]
91. Utah St (4-8) [0.1998]
92. Louisiana Tech (4-8) [0.1984]
93. UTEP (4-8) [0.1947]
94. Indiana (4-8) [0.1935]
95. Vanderbilt (2-10) [0.1921]
96. Tulsa (5-7) [0.1912]
97. San Diego St (4-8) [0.1860]
98. Washington St (1-11) [0.1816]
99. Colorado St (3-9) [0.1813]
100. Maryland (2-10) [0.1808]
101. Buffalo (5-7) [0.1735]
102. Florida Atlantic (5-7) [0.1715]
103. Toledo (5-7) [0.1697]
104. Florida Int'l (3-9) [0.1677]
105. Tulane (3-9) [0.1555]
106. Kent St (5-7) [0.1471]
107. San Jose St (2-10) [0.1420]
108. New Mexico St (3-10) [0.1388]
109. Army (5-6) [0.1341]
110. Rice (2-10) [0.1262]
111. Western Michigan (5-7) [0.1256]
112. Memphis (2-10) [0.1172]
113. Arkansas St (4-8) [0.1162]
114. Miami OH (1-11) [0.1088]
115. New Mexico (1-11) [0.1048]
116. Akron (3-9) [0.1004]
117. North Texas (2-10) [0.0838]
118. Ball St (2-10) [0.0634]
119. Eastern Michigan (0-12) [-0.0003]
120. Western Kentucky (0-12) [-0.0032]
Conference Rankings (Average Per Team):
SEC 0.6927
Pac10 0.5540
BigEast 0.5414
ACC 0.5092
Big10 0.4422
Big12 0.4317
MWC 0.3860
WAC 0.3326
FBSInd 0.3163
CUSA 0.2848
MAC 0.1949
SunBelt 0.1909
Non-FBS -0.0829

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