March Madness FiveThirtyEight Model Challenge
As part of the Advanced Statistics Class I’m teaching this term, I’ve asked students to build a regression model attempting to replicate Nate Silver’s March Madness Sweet 16 Predictions.
Nate’s model is built using a variety of factors:
- Composite of five computer power ratings including Ken Pomeroy’s ratings, Jeff Sagarin’s Predictor ratings, Sonny Moore’s ratings, Jeff Sokol’s LRMC ratings and ESPN’s Basketball Power Index.
- NCAA Selection Committee Seeding Order
- Preseason rankings from both the AP and the USA Today Coaches Poll
Nate also makes adjustments for injuries and travel distance but we didn’t have time to include these factors in class.
In preparation for class today I built a model using only two variables: NCAA Seed Order and Sonny Moore’s ratings and was able to reproduce Nate’s % Chance of Reaching Sweet 16 with a fairly high level of accuracy. For stats nerds here is some model output:
| Regression Statistics | |
| Multiple R | 0.9694 |
| R Square | 0.9398 |
| Adjusted R Square | 0.9370 |
| Standard Error | 6.3795 |
| Observations | 68 |
| ANOVA | |||||
| df | SS | MS | F | Significance F | |
| Regression | 3 | 40662.94 | 13554.31 | 333.05 | 0.00000000 |
| Residual | 64 | 2604.68 | 40.70 | ||
| Total | 67 | 43267.62 |
I don’t want to share the regression equation itself because that might ruin the fun for my students. But, here is a comparison chart showing my predictions versus Nate’s along with the raw data further below. You are welcome to use these data for the Billion Dollar Bracket Challenge. All I ask is if Warren Buffet sends you a big check please send me half. Might cover a small portion of the college tuition expenses for my 3 kids over the next 15-20 years.
| Team | Nate | Me | Residuals |
| Florida | 83.9460 | 83.8147 | 0.1313 |
| Louisville | 78.3270 | 79.7111 | -1.3841 |
| Michigan | 73.8490 | 66.7303 | 7.1187 |
| Arizona | 72.6880 | 80.4752 | -7.7872 |
| Wisconsin | 71.8360 | 61.6824 | 10.1536 |
| Virginia | 70.7820 | 76.3386 | -5.5566 |
| Duke | 70.4410 | 60.9141 | 9.5269 |
| Kansas | 67.0390 | 59.9023 | 7.1367 |
| Michigan State | 66.5930 | 55.4831 | 11.1099 |
| Villanova | 64.4580 | 71.9180 | -7.4600 |
| UCLA | 62.6920 | 46.1987 | 16.4933 |
| Wichita State | 59.3560 | 67.9480 | -8.5920 |
| Creighton | 54.3760 | 53.2811 | 1.0949 |
| Syracuse | 50.1450 | 48.7612 | 1.3838 |
| Iowa State | 46.3800 | 45.9931 | 0.3869 |
| San Diego State | 42.5320 | 34.9598 | 7.5722 |
| Ohio State | 40.0770 | 35.8186 | 4.2584 |
| North Carolina | 36.3760 | 33.4644 | 2.9116 |
| Kentucky | 33.9020 | 22.6230 | 11.2790 |
| Baylor | 33.8120 | 26.6866 | 7.1254 |
| Oklahoma | 33.3590 | 30.5882 | 2.7708 |
| Virginia Commonwealth | 28.6660 | 37.0897 | -8.4237 |
| Connecticut | 26.3150 | 28.9027 | -2.5877 |
| New Mexico | 22.1610 | 22.2339 | -0.0729 |
| Cincinnati | 19.4840 | 36.6941 | -17.2101 |
| Oregon | 19.1420 | 21.3953 | -2.2533 |
| Memphis | 16.6600 | 14.6652 | 1.9948 |
| North Dakota State | 14.5470 | 4.7441 | 9.8029 |
| Oklahoma State | 14.4280 | 19.1470 | -4.7190 |
| Pittsburgh | 13.6190 | 20.2434 | -6.6244 |
| Gonzaga | 12.6190 | 22.0542 | -9.4352 |
| Texas | 12.6190 | 16.2179 | -3.5989 |
| Arizona State | 12.5200 | 5.6537 | 6.8663 |
| Providence | 12.1140 | 11.0555 | 1.0585 |
| St. Louis | 12.0300 | 25.9545 | -13.9245 |
| Tennessee | 11.9940 | 18.3063 | -6.3123 |
| George Washington | 11.9910 | 8.6488 | 3.3422 |
| Harvard | 11.6070 | 8.6408 | 2.9662 |
| New Mexico State | 9.5620 | -0.3737 | 9.9357 |
| Iowa | 9.3960 | 14.8457 | -5.4497 |
| Nebraska | 9.1640 | 12.2987 | -3.1347 |
| Stanford | 8.9180 | 10.9164 | -1.9984 |
| Saint Joseph’s | 8.3540 | 11.1070 | -2.7530 |
| Dayton | 7.6260 | 6.1262 | 1.4998 |
| BYU | 6.9540 | 9.0155 | -2.0615 |
| Kansas State | 6.6050 | 10.5180 | -3.9130 |
| Massachusetts | 6.2340 | 15.3853 | -9.1513 |
| North Carolina Central | 5.1300 | 3.1089 | 2.0211 |
| Xavier | 4.8220 | 8.8253 | -4.0033 |
| Tulsa | 4.4580 | 4.2679 | 0.1901 |
| Stephen F. Austin | 4.1830 | -2.4063 | 6.5893 |
| Louisiana-Lafayette | 2.6470 | -0.4934 | 3.1404 |
| Manhattan | 2.5570 | 1.7351 | 0.8219 |
| Delaware | 2.3160 | -1.5629 | 3.8789 |
| North Carolina State | 2.2640 | 6.6363 | -4.3723 |
| Colorado | 2.2420 | 6.3846 | -4.1426 |
| Western Michigan | 2.1510 | -0.7670 | 2.9180 |
| American University | 2.0690 | 3.2675 | -1.1985 |
| Mercer | 1.9350 | 1.6642 | 0.2708 |
| Eastern Kentucky | 1.8820 | -0.5050 | 2.3870 |
| Wofford | 1.0120 | -0.3110 | 1.3230 |
| Milwaukee | 0.8740 | -1.6194 | 2.4934 |
| Coastal Carolina | 0.5670 | -0.1038 | 0.6708 |
| Weber State | 0.2660 | 2.1002 | -1.8342 |
| Albany | 0.1130 | 4.7816 | -4.6686 |
| Cal Poly | 0.0910 | 5.2246 | -5.1336 |
| Mount St. Mary’s | 0.0800 | 3.0392 | -2.9592 |
| Texas Southern | 0.0450 | 1.9538 | -1.9088 |