Wednesday, November 27, 2013

Statistical College Basketball Rankings, Vol. II

Below are my rankings for the Top 50 college basketball teams. Statistics/ratings are through games played on Monday, 11/25. Louisville, the former #1, dropped to #5 following their loss to UNC. Kansas is the new #1 team and I suspect they'll be near the top much of the season. Dropping out were: Indiana, Georgetown, Virginia, NC State, Arizona State, Southern Mississippi, Colorado State, and Alabama. Replacing those teams were: North Carolina, Texas, Stanford, Tennessee, Dayton, Belmont, Xavier, and Mississippi. As I expected with it being early in the season, some teams fluctuated quite a bit, and I think that will continue for maybe another month. It seems there is not much separating teams ranked 35-50 from team ranked 51-65, so look for another ten or so teams to move up in my Top 50 next week.

Rank Prev.
Rank
TEAM Record Weighted
Metric
2013-14
Metric Rank
AP Rank
1 2 Kansas (4-0, 0-0) 6.125 7 2
2 16 Florida (5-1, 0-0) 15.585 9 15
3 7 Pittsburgh (5-0, 0-0) 16.89 13 39
4 20 Syracuse (5-0, 0-0) 18.215 34 8
5 1 Louisville (5-1, 0-0) 18.228 44 9
6 18 Memphis (2-1, 0-0) 18.49 6 21
7 3 Arizona (5-0, 0-0) 18.72 27 4
8 5 Ohio State (5-0, 0-0) 19.67 28 7
9 13 Oklahoma St (5-0, 0-0) 20.31 1 5
10 11 Michigan St (6-0, 0-0) 20.665 8 1
11 14 Iowa State (5-0, 0-0) 22.55 2 17
12 15 Wisconsin (6-0, 0-0) 22.89 25 10
13 10 UCLA (5-0, 0-0) 28.575 19 19
14 4 Duke (5-1, 0-0) 32.08 84 6
15 22 Kentucky (5-1, 0-0) 32.275 4 3
16 19 Minnesota (5-1, 0-0) 33.205 15 43
17 42 Wichita St (7-0, 0-0) 33.55 23 12
18 23 Baylor (5-0, 0-0) 33.68 36 18
19 26 Colorado (6-1, 0-0) 33.685 11 36
20 21 Oregon (4-0, 0-0) 34.115 43 14
21 NR N Carolina (4-1, 0-0) 34.292 12 16
22 40 California (5-0, 0-0) 36.675 24 NR
23 31 Villanova (4-0, 0-0) 37.895 22 37
24 43 Connecticut (6-0, 0-0) 38.755 30 13
25 25 BYU (5-2, 0-0) 41.125 29 NR
26 30 Cincinnati (4-0, 0-0) 43.48 57 42
27 37 Iowa (5-0, 0-0) 44.865 32 23
28 32 St Marys (5-0, 0-0) 45.55 58 NR
29 NR Texas (4-1, 0-0) 45.58 17 NR
30 35 Creighton (4-0, 0-0) 45.645 45 20
31 36 Oklahoma (4-1, 0-0) 46.105 33 NR
32 45 Arkansas (3-1, 0-0) 46.34 18 NR
33 39 Butler (4-0, 0-0) 46.515 65 NR
34 41 San Diego St (2-1, 0-0) 47.28 50 NR
35 NR Stanford (5-1, 0-0) 48.085 39 NR
36 27 Illinois (5-0, 0-0) 48.745 77 44
37 34 New Mexico (4-1, 0-0) 49.138 38 26
38 46 U Mass (6-0, 0-0) 49.3 20 24
39 12 Gonzaga (4-1, 0-0) 49.47 55 11
40 29 Saint Louis (5-0, 0-0) 50.22 67 NR
41 9 Marquette (3-2, 0-0) 50.898 52 25
42 NR Tennessee (3-1, 0-0) 50.9625 5 41
43 NR Dayton (5-0, 0-0) 52.36 35 NR
44 17 Missouri (5-0, 0-0) 54.63 94 NR
45 50 LSU (3-1, 0-0) 54.65 14 NR
46 NR Belmont (6-1, 0-0) 55.263 68 33
47 NR Xavier (5-0, 0-0) 55.57 31 38
48 NR Mississippi (3-0, 0-0) 55.755 70 NR
49 28 VCU (4-2, 0-0) 57.005 53 27
50 6 Michigan (4-2, 0-0) 57.67 10 22

Wednesday, November 20, 2013

Developing Statistical College Basketball Rankings

In past years, I have enjoyed making a college basketball 'Top 50' during the course of a season. However, it was essentially an opinion poll, based off of final score, and perceived strength of opponent. In essence, there was no way of validating it any higher than the AP Top 25. This season, I have decided to go from a near 100% opinion-based poll, to a near 100% statistical-based poll. There are a couple of constraints that will prevent this from being as timely, accurate, and predictive as Ken Pomeroy's (http://kenpom.com/index.php) rankings: a.) I am not a computer scientist and have no idea how to develop code to make this a more automated process, and; b.) I am not a statistician, so it is above my head as to how to develop a unique methodology or statistical testing to take this to the next level. So I'll do the best I can with data that is freely available and my trusty sidekick OpenOffice Calc.

There are five key factors I use in developing the strength of a team both offensively and defensively. For offense, they are:
  1. Points Per Possession, or Offensive Efficiency
  2. Effective Field Goal %
  3. Free Throws Attempted Per Field Goal Attempted
  4. Offensive Rebounding %
  5. Turnover %
Conversely, the five key factors on defense are:
  1. Opponent Points Per Possession, or Defensive Efficiency
  2. Opponent Effective Field Goal %
  3. Opponent Free Throws Attempted Per Field Goal Attempted
  4. Opponent Offensive Rebounding %
  5. Opponent Turnover %
For reference, see http://kenpom.com/blog/index.php/weblog/entry/help_with_team_page for a description of these stats. A big thanks goes to Team Rankings for making all of these statistics freely available (http://www.teamrankings.com/ncb/stats/). Without that site, I couldn't embark on this endeavor without shelling out some cash. Offensive and defensive metrics were given a 75/25 adjustment based off strength of schedule. For example, say Team A has the #12 offense but #100 strength of schedule; while Team B has the #40 offense with the #4 strength of schedule. Team A would receive an 'Adjusted Offense Rank' of 34 [(0.75*12)+(0.25*100)], while Team B would Receive an 'Adjusted Offense Rank' of 31 [(0.75*40)+(0.25*4)]. A slightly worse offense with a noticeably tougher schedule, yields a better adjusted offense.

Before I post my Top 50, keep in mind the ultimate caveat, in that it is early in the season and the sample size is small. With that said, I weighed the current metric, with recruiting rankings (http://247sports.com/Season/2013-Basketball/CompositeTeamRankings), and a blend of the final 2012-13 final rankings from Ken Pomeroy (http://kenpom.com/index.php?y=2013) and Team Rankings (http://www.teamrankings.com/ncaa-basketball/ranking/overall-power-ranking-by-team?rating_date=2013-04-09). I have currently placed a heavier weight towards last years final rankings (about 48%), while recruiting received the lowest weight (about 17%). This season's metric rank receives the remaining weighting (about 35%). There is no rhyme or reason for those values other than some trial and error on my part. The lower the score in the Weighted Metric, the better. As the season progresses, those weights will be modified, ultimately until the point that this season's metric rank accounts for the entire 100%. I have developed a "Bad Loss Correction" to adjust a team's weighted rank when they lose to a team perceived to be worse than them. For now, I will keep my methodology behind that private, as I want to test it for a while to see how well it works.

To give you an idea of the direction a team is headed, I am posting this year's metric rank to the right of my current blended rank. This will give you an idea of whether a team is rated too high or low because of how the finished last year. For example, I have Kentucky rated #22, but they are playing as the #1 overall team this season, despite their loss to Michigan State. One last thing, current rankings are through games played on Sunday, 11/18/2013. Due to time constraints, I will likely update this only once per week - probably every Monday to coincide with the latest AP rankings (http://collegebasketball.ap.org/poll). Alright, here are my current rankings:

Rank TEAM Weighted
Metric
2013-14
Metric Rank
AP Rank
1 Louisville 8.26 19 3
2 Kansas 9.23 16 2
3 Arizona 10.095 2 5
4 Duke 10.69 22 6
5 Ohio State 11.39 4 8
6 Michigan 12.984 9 15
7 Pittsburgh 14.475 6 36
8 Indiana 20.045 50 27
9 Marquette 22.78 33 25
10 UCLA 23.745 5 22
11 Michigan St 23.77 17 1
12 Gonzaga 23.865 8 13
13 Oklahoma St 24.105 12 7
14 Iowa State 24.275 7 21
15 Wisconsin 26.685 36 12
16 Florida 27.053 21 16
17 Missouri 27.375 15 38
18 Memphis 27.41 42 11
19 Minnesota 29.065 3 39
20 Syracuse 29.6 67 9
21 Oregon 29.63 30 17
22 Kentucky 31.24 1 4
23 Baylor 31.955 31 20
24 Georgetown 33.435 39 47
25 BYU 34.915 11 44
26 Colorado 36.1 18 37
27 Illinois 36.325 41 NR
28 VCU 36.525 13 10
29 Saint Louis 36.765 28 40
30 Cincinnati 36.925 38 42
31 Villanova 37.205 20 33
32 St Marys 38.305 37 NR
33 Virginia 38.43 24 28
34 New Mexico 38.94 35 19
35 Creighton 39.435 27 23
36 Oklahoma 39.55 14 NR
37 Iowa 42.795 26 26
38 NC State 43.58 69 NR
39 Butler 46.17 64 NR
40 California 46.335 52 NR
41 San Diego St 46.935 49 NR
42 Wichita St 49.765 70 14
43 Connecticut 50.83 65 18
44 Arizona St 52.105 23 32
45 Arkansas 56.345 47 NR
46 U Mass 63.13 34 43
47 S Mississippi 65.04 58 NR
48 Colorado St 65.415 87 NR
49 Alabama 65.545 83 NR
50 LSU 66.525 59 NR

[Note: The following AP ranked teams are not in my Top 50...#24 North Carolina (61st), #29 Harvard (75th), #30 Boise State (56th), #31 Belmont (78th), #34 Xavier (54th), #35 Tennessee (55th), #41 Florida State (62nd), #45 Indiana State (79th), and #46 Notre Dame (60th)]