I've finally located and fixed the bug that was causing the point spreads to be underestimated, and I figured now was as good a time as any to finally get a post up explaining just how TAPE and TAPE projections work.
If you're a baseball stathead or you're familiar with Ken Pomeroy's ratings, you've probably heard of the Log5 method for predicting the outcome of a given event. Simply put, it says that a team's expected winning percentage in a given game can be predicted using the following formula:
Where T is the team's winning percentage and P is the opponent's winning percentage. So if you have a full baseball season's worth of data, or a really good adjusted ratings system like KenPom's (or even the TAPE ratings), you can get a pretty good handle on what the odds are for a given game.
There's a much more powerful variation on the theme of Log5, though, and it's way more useful. Instead of having an implied mean of .500 for all teams, the following formula (which I stumbled upon here) has league average as its own variable:
In this case, the formula gives the expected batting average for a hitter with a batting average of B facing a pitcher with a batting-average-against of P in a league where the overall batting average for all players is L. The good news for us is that it works just as well in basketball as it does in baseball. Field goal percentage, rebounding percentage, the ratio of three-point attempts to field goal attempts, and anything else that is (or can be) expressed as a number between zero and 1 can be predicted with a suitable degree of accuracy using the above formula.
Using this method and a table of each team's double-neutral (i.e. what the team would be expected to do on a neutral court against average competition) values in a number of categories, it's possible to not only predict teams' performances in any given category, but also, using a probablistic model of a possession, to build a complete predicted line score for any matchup.
The full slate of games is after the jump. Tipoff Visitors TAPE Predicts Home Line O/U % Conf. 6:30 PM Michigan St. 71.9 at 69.3 Penn St. +6.0 136 57.4% BigTen 7:00 PM Binghamton 65.2 at 70.3 Albany 64.5% A-East Holy Cross 56.2 at 54.7 Army 54.6% Pat Sacred Heart 67.2 at 61.7 Bryant 65.2% Elon 53.9 at 84.4 Davidson -23.5 137.5 98.6% SoCon Hofstra 58.7 at 63.0 Drexel -4.0 122 62.5% CAA Geo. Washington 60.6 at 78.8 Duquesne -10.5 146 90.1% A-10 Duke 79.2 at 67.1 Georgia Tech +12.0 148.5 80.0% ACC Maine 59.6 at 62.7 Hartford 59.0% A-East N.C. Wilmington 67.2 at 91.3 James Madison -15 153.5 94.8% CAA Bowling Green 63.5 at 68.0 Kent St. -7.5 135 62.7% MAC Colgate 62.5 at 66.6 Lafayette 61.7% Pat Navy 69.8 at 74.5 Lehigh 62.7% Pat N.J.I.T. 45.8 at 71.4 Loyola (MD) 97.3% Ohio 55.0 at 67.8 Miami (OH) -9.0 122 83.2% MAC UMBC 65.1 vs 60.1 New Hampshire 64.9% A-East Temple 71.7 at 65.8 Pennsylvania +9.0 138.5 66.3% South Florida 51.5 at 74.7 Pittsburgh -21.0 131 95.8% B-East S. Carolina St. 58.4 at 63.1 Savannah St. 63.8% St. Joseph's 67.0 at 64.9 St. Bonaventure +4.5 137 56.2% A-10 VCU 75.7 at 67.0 Towson +9.0 135.5 72.8% CAA Richmond 64.2 at 69.1 Virginia Tech -8.0 131 64.2% Toledo 57.2 at 64.1 W. Michigan -10.0 124.5 69.7% MAC George Mason 61.7 at 56.7 William & Mary +6.0 122.5 65.0% CAA Gardner-Webb 66.9 at 66.3 Winthrop 51.6% B-Sou 7:30 PM Bucknell 56.7 at 70.2 American 83.9% Pat Vermont 70.7 at 73.2 Boston U. 56.7% A-East La Salle 69.3 at 76.4 Charlotte -5.0 145 69.1% A-10 Rutgers 59.9 at 70.1 Cincinnati -9.0 130 77.1% B-East Fordham 48.8 at 77.1 Dayton -21.0 125.5 98.1% A-10 Syracuse 67.2 at 78.8 Georgetown -6.5 142.5 79.2% B-East Texas Pan Amer. 63.6 at 61.3 N.C. Central 56.9% UTSA 66.7 at 67.1 Nicholls St. 51.3% S'land 8:00 PM Florida 70.0 at 69.7 Auburn +3.0 138 50.8% SEC Stephen F. Austin 66.2 at 51.5 Central Arkansas 87.3% S'land Nebraska 60.8 at 57.1 Iowa St. +1.5 120 61.2% Big 12 South Carolina 70.6 at 74.1 LSU -3.5 144 59.6% SEC Arkansas 74.3 at 80.7 Mississippi -1.5 146.5 66.9% SEC Alabama 62.6 at 72.7 Mississippi St. -7.0 136 76.2% SEC SMU 63.6 at 65.3 Rice -3.0 130 55.0% C-USA Massachusetts 59.7 at 66.3 Saint Louis -3.5 129 69.0% A-10 Northwestern St. 68.4 at 85.0 SE Louisiana 87.4% S'land Texas St. 75.4 at 77.0 Texas A&M C.C. 54.4% S'land Southern Miss 62.7 at 56.5 Tulane +3.0 123 68.4% C-USA Lamar 75.3 at 81.5 TX Arlington 66.4% S'land Georgia 58.2 at 71.9 Vanderbilt -10.5 132 83.4% SEC Marshall 55.8 vs 77.4 West Virginia -15.5 136 94.6% San Diego St. 76.4 at 67.9 Wyoming +6.0 139 72.3% MWC 8:05 PM Southern Ill. 60.3 at 72.8 Creighton -10.5 129.5 81.9% Valley Drake 64.0 at 74.5 Illinois St. -8.5 136 77.1% Valley Wichita St. 54.4 at 56.6 Missouri St. -4.0 116 56.7% Valley 8:30 PM Michigan 61.6 at 70.5 Illinois -7.0 127 74.5% BigTen 9:00 PM Wake Forest 80.4 at 75.4 Boston Coll. +3.5 155.5 63.4% ACC UNLV 73.3 at 68.3 Colorado St. +7.5 140.5 63.7% MWC Maryland 61.4 at 75.1 Miami (FL) -6.5 141 83.0% ACC Colorado 59.8 at 81.7 Missouri -18.0 138 94.6% Big 12 9:05 PM Houston 71.7 at 74.3 UTEP -4.5 149 57.1% C-USA 9:30 PM Baylor 71.6 at 69.0 Texas A&M +1.5 139.5 57.4% Big 12 10:00 PM Utah 61.5 at 53.5 Air Force +8.0 122 73.3% MWC CSU Northridge 66.9 at 65.9 UC Riverside -1.0 132.5 53.0% B-West Point spreads compiled from OddsShark.com. Updated 11:42 PM EST
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