Sunday, August 4, 2013

2013 NFL Rankings - First Look

As they did last year, Cantor Gaming has released point spreads for every NFL game this season, up to week 16. My rankings are based on what the betting market thinks, as opposed to actual game data, so I can get a jump start the interminable "who's better" debates before we've even seen a complete game of pre-season football.

Opening up the Cantor Gaming Black Box


With 16 weeks of data to work with, it's a fairly straightforward analysis to derive an implied team power ranking from the point spreads. However, I aim to take things one step further and tease out implied team-specific home field advantage from that same data set. To do this, I treat each team as if it were really two teams: the team they are when at home, and the team they are when they're on the road. Each of those teams will have a ranking, as implied by the point spreads, and the gap between the two can be considered a measure of that team's home field advantage.
The table below summarizes the results of my analysis.  An explanation of the columns:

  • 2012 - The team's ranking as of the end of the regular season, according to my betting market rankings
  • GPF - Generic Points Favored.  What you would expect the team to be favored by on a neutral field against a league average opponent
  • aGPF - Away Generic Points Favored.  The implied GPF of the team if you looked only at their road games.
  • hGPF - Home Generic Points Favored.  The implied GPF of the team if you looked only at their home games.
  • HFA - Home Field Advantage.  This is just the difference between aGPF and hGPF, along with the corresponding rank.

2013 NFL Rankings
Rank Team 2012  GPF  aGPF hGPF HFA
1  DEN 3 4.6 3.0 6.2 3.1 1
2  SEA 5 4.5 3.5 5.5 2.0 17
3  SF 4 4.4 3.2 5.6 2.4 6
4  NE 1 4.3 3.5 5.1 1.6 26
5  GB 2 3.1 2.0 4.1 2.1 13
6  ATL 7 2.5 1.2 3.8 2.6 2
7  BAL 10 2.2 1.0 3.4 2.4 4
8  NO 11 2.1 1.1 3.0 1.9 18
9  PIT 12 1.7 0.9 2.5 1.6 27
10  HOU 6 1.5 0.4 2.5 2.0 15
11  CHI 9 1.1 0.0 2.1 2.1 12
12  NYG 8 1.0 -0.2 2.2 2.4 5
13  CIN 14 1.0 0.1 1.9 1.8 22
14  WAS 15 0.9 0.1 1.8 1.7 25
15  MIN 16 0.4 -0.7 1.5 2.2 9
16  DAL 13 0.4 -0.5 1.3 1.9 20
17  DET 18 0.2 -0.8 1.1 1.9 21
18  CAR 17 -0.3 -1.0 0.4 1.3 30
19  MIA 21 -0.5 -1.6 0.6 2.2 10
20  TB 20 -0.9 -1.6 -0.1 1.4 29
21  PHI 27 -1.0 -2.1 0.0 2.1 14
22  SD 19 -1.1 -1.7 -0.5 1.1 31
23  IND 24 -1.3 -2.4 -0.2 2.1 11
24  STL 22 -1.5 -2.7 -0.4 2.3 8
25  NYJ 23 -1.9 -2.9 -1.0 1.9 19
26  KC 32 -2.2 -2.9 -1.5 1.4 28
27  BUF 26 -3.0 -3.9 -2.1 1.7 23
28  CLE 25 -3.1 -3.9 -2.2 1.7 24
29  ARZ 28 -3.6 -4.6 -2.7 2.0 16
30  TEN 29 -4.2 -4.7 -3.7 1.1 32
31  OAK 30 -5.0 -6.3 -3.8 2.5 3
32  JAC 31 -6.1 -7.3 -5.0 2.4 7

Some observations:
  • The top 5 (Broncos, Seahawks, Niners, Patriots, Packers) are unchanged from last year, just somewhat reshuffled.
  • Not a whole lot of movement in general, with the Chiefs and Eagles moving the most, both jumping six spots from their lowly 2012 positions
  • The home field advantage numbers don't appear to track that closely to historical results.  The Broncos are at the top, but their home away splits are below average (since 2006, their average scoring margin is 3.7 points higher at home, which is 19th overall).  In contrast, the Seahawks have had the strongest home/away split, with home scoring margins 11.8 points higher than on the road for the same time period.  But Cantor doesn't appear to put too much credibility in those results. They have the Seahawks right in the middle in terms of implied home field advantage.