2018-19 National Basketball Association Computer Ratings


Introduction

This is my rough attempt at a computer rating that can, among other things, come somewhat close to predicting final game scores. The actual computer rating, which describes team performance based on games played to date, is found under the "Rating" column. To determine a hypothetical margin of victory, use the "Points" column (just subtract the teams in question) and add in the home field/court advantage, which is listed on the right. It usually is around 2.5 points for basketball. All of the games in the predictions list already have home advantage taken into account.


Ratings last updated Friday 06/14/19, 08:08 AM ET Rank Team W L Rating Points BCS 1 Milwaukee 70 27 3.45 58.95 2 2 Toronto 74 32 3.02 56.74 1 3 Golden State 71 33 2.72 56.13 3 4 Houston 59 34 2.49 55.72 4 5 Utah 51 36 2.00 55.44 7 6 Portland 61 37 1.93 54.11 5 7 Denver 60 35 1.88 54.06 6 8 Philadelphia 58 36 1.41 52.76 8 9 Boston 54 37 1.26 53.38 11 10 Oklahoma City 49 38 1.15 53.17 12 Rank Team W L Rating Points BCS 11 San Antonio 51 37 1.09 51.99 9 12 LA Clippers 50 38 0.90 51.22 10 13 Indiana 48 38 0.57 52.18 13 14 Orlando 43 44 0.02 49.88 14 15 Brooklyn 44 43 -0.18 49.04 15 16 Miami 39 43 -0.30 49.49 18 17 Charlotte 39 43 -0.35 49.01 16 18 Detroit 41 45 -0.42 48.86 17 19 Sacramento 39 43 -0.54 48.55 19 20 LA Lakers 37 45 -0.55 48.83 20 Rank Team W L Rating Points BCS 21 Minnesota 36 46 -0.67 48.62 21 22 Dallas 33 49 -0.87 49.07 23 23 New Orleans 34 48 -1.05 48.49 24 24 Memphis 33 49 -1.15 47.64 22 25 Washington 32 50 -1.53 46.83 25 26 Atlanta 28 54 -2.33 43.85 26 27 Chicago 22 60 -3.13 42.28 27 28 Phoenix 19 63 -3.47 41.32 28 29 Cleveland 19 63 -3.63 41.01 29 30 New York 17 65 -3.74 41.38 30
(The "BCS style" ranking is one based entirely on wins and losses, similar to what is used in college football.)

 

PREDICTIONS FOR UPCOMING GAMES Date Away Team Home Team Total Prediction ----------- -------------------- -------------------- ----- --------------

Current home field advantage is: 2.74 MAE for games to date: 10.01 These ratings fit to produce 0.67 of the correct winners. Pct when predicted MOV is above 5.49: 0.80 A favored away team rarely loses when favored by more than -4.64. A favored home team rarely loses when favored by more than 7.28.

Above are some statistics about the ratings model. Each team has its own home "field" advantage, but the average all of them is shown here. The MAE is the mean absolute error of the ratings fit to all the games played to date. This number is usually larger than you think it should be, but it's a good measure of how variable (or maybe "predictable") game outcomes can be.

Immediately below that, you can see how this best fit does in retro-predicting (there's a better word I'm sure) just the game winners. My favorite stats are the last two--when the home or away team is favored by the given margin, they only lose 30 percent of the time. This is the kind of information that people in the sports wagering world might find useful.


About the author

I have a Ph.D. in Atmospheric Science from the University of Alabama in Huntsville. I am now a faculty member at Indiana University in Bloomington, teaching courses in the broad areas of weather and climate. Don't hesitate to contact me using this email form if you have questions or non-hateful comments. shopify stats