16 March 2011

Rating Systems and March Madness Brackets, Part III

There's still time to join the RationalPastime.com ESPN Tournament Challenge group. Open to everyone, brackets lock at the beginning of Thursday's games.

To round out our look at the different rating methodologies and how they apply to brackets (Part I, Part II), we analyze three more systems: the Nolan Power Index, the ESPN National Bracket (as of Noon EDT Wednesday, subject to change), and the Vegas odds for winning the region and the Final Four.

The Nolan Power Index is a power rating system, but NPI isn't nearly as chalky as other power systems such as Moore, Sagarin or Pomeroy. Nolan is particularly aggressive with some upsets: they have UAB beating West Virginia (assuming UAB wins their play-in), Richmond topping Vanderbilt, Utah State over Kansas State, Belmont shocking Wisconsin, and Gonzaga advancing against St. John's. Beyond that, they actually have Richmond advancing to the Sweet Sixteen and Utah State advancing to the Elite Eight.

The other two brackets--Vegas and ESPN National--are almost pure chalk. This is unsurprising, but it's notable that most of the power systems agree with the crowd-sourced systems.

Upset Index (Seed Differential * [2 ^ Round / 2])

Field 64 Field 32 Sweet 16 Elite 8 Overall
Vegas 6 0 0 0 6
ESPN National Bracket 5 0 4 0 9
Sonny Moore 8 0 4 0 12
FiveThirtyEight 14 0 4 0 18
Jeff Sagarin 14 0 8 0 22
Pomeroy 25 0 12 0 37
NCAA 9 16 4 24 53
ESPN Decision Tree 27 22 12 16 77
Lunardi RPI 25 8 40 8 81
Nolan Power Index 30 16 52 8 106
LRMC Bayesian 34 12 72 80 198
Mean 19 7 19 12 57

None of the final three systems offer a new perspective on the final four. Vegas and the ESPN community agree with most of the systems, and the NPI system predicts the same Final Four as NCAA Official RPI.

Final Four Picks East West Southwest Southeast
Vegas OSU (1) Duke (1) Kansas (1) Pitt (1)
ESPN National Bracket OSU (1) Duke (1) Kansas (1) Pitt (1)
Sonny Moore OSU (1) Duke (1) Kansas (1) Pitt (1)
FiveThirtyEight OSU (1) Duke (1) Kansas (1) Pitt (1)
Jeff Sagarin OSU (1) Duke (1) Kansas (1) Pitt (1)
Pomeroy OSU (1) Duke (1) Kansas (1) Pitt (1)
NCAA OSU (1) SDSU (2) Kansas (1) BYU (3)
ESPN Decision Tree OSU (1) Duke (1) Kansas (1) BYU (3)
Lunardi RPI OSU (1) Texas (4) Kansas (1) BYU (3)
Nolan Power Index OSU (1) SDSU (2) Kansas (1) BYU (3)
LRMC Bayesian OSU (1) Duke (1) Kansas (1) Belmont (13)

Check out the details on the upset picks for each system after the jump. Picks for other systems available in Parts I and II of this series.
 
Vegas: 6
Field 64 Field 32 Sweet 16 Elite 8
Villanova (9) None None None
George Mason (8)






Tennessee (9)


Michigan (8)






Old Dominion (9)


Butler (8)






Michigan St (10)


UCLA (7)






ESPN National Bracket: 9
Field 64 Field 32 Sweet 16 Elite 8
Villanova (9) None Connecticut (3)
George Mason (8)
San Diego St (2)




Tennessee (9)


Michigan (8)






Illinois (9)


UNLV (8)






Michigan St (10)


UCLA (7)










Nolan Power Index: 106
Field 64 Field 32 Sweet 16 Elite 8
UAB (12) Richmond (12) Purdue (3) San Diego St (2)
West Virginia (5) Louisville (4) Notre Dame (2) Duke (1)




Tennessee (9)
Utah St (12)
Michigan (8)
Pittsburgh (1)




Richmond (12)
BYU (3)
Vanderbilt (5)
Florida (2)




Old Dominion (9)


Butler (8)






Utah St (12)


Kansas St (5)






Belmont (13)


Wisconsin (4)






Gonzaga (11)


St. John's (6)



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