## Analyzing NFL SRS Ratings Through 3.0625 Weeks

I thought it would be fun to create NFL SRS ratings through three weeks and one Thursday Night football game. After just 3.0625 weeks, all data are heavily influenced by events that are unlikely to be repeated.  Remember Neil’s old post that showed how for teams with any record, to determine their “true winning percentage”, we need to add 5.5 wins and 5.5 losses. That means through three weeks, a team’s actual record should still be regressed to league average by nearly 80%; in other words, take all these ratings with a big grain of salt.  But there’s no reason not to run the numbers, so here are the customary parameters:

• Home wins of less than 3 points are treated as ties;
• For all other games, give the road team 3 points.  From there, wins of fewer than 7 points are treated as 7-point wins;
• Wins of between 7 and 24 points (after adjusting for home field) are treated as they are.  So a 14-point home win is a 11-point MOV, and a 17-point road win is a 20-point MOV;
• Wins of greater than 24 points convert to a Margin of Victory that is the average of 24 and the HFA-adjusted MOV.  So the Falcons get a 31.5 for beating Tampa Bay by 42 at home, while the Giants get a MOV of 29 for winning in Washington by 31.

From there, we simple use the typical SRS iteration process to produce a set a season ratings. Those are presented below:

RkTeamRecMOVSOSSRS
1Cincinnati Bengals3-014.812.727.5
2Baltimore Ravens2-14.717.522.2
3San Diego Chargers2-17.311.719.1
4Arizona Cardinals3-078.815.8
5Atlanta Falcons2-19.26.415.5
6Pittsburgh Steelers2-13.711.315
7Seattle Seahawks2-15.75.110.8
8Cleveland Browns1-2-4.714.710
9Buffalo Bills2-12.75.98.5
10Chicago Bears2-152.47.4
11New Orleans Saints1-20.36.66.9
12San Francisco 49ers1-2-1.38.16.8
13Detroit Lions2-14.3-0.63.7
14Carolina Panthers2-10.71.11.8
15Dallas Cowboys2-14-2.91.1
16New York Giants2-21.8-1.10.6
17Denver Broncos2-12.3-1.70.6
18Tennessee Titans1-2-7.88.20.4
19New England Patriots2-17.3-10.5-3.1
20Kansas City Chiefs1-2-1.3-2.6-4
21Green Bay Packers1-2-6.32.1-4.2
22Houston Texans2-15.7-11.4-5.8
23Minnesota Vikings1-2-1.8-4-5.9
24New York Jets1-2-3.7-4.5-8.2
25Miami Dolphins1-2-9.30.5-8.9
26Indianapolis Colts1-24.3-16.4-12.1
28Tampa Bay Buccaneers0-3-15.80.5-15.3
29St. Louis Rams1-2-9.2-6.7-15.9
30Oakland Raiders0-3-11-5.7-16.7
31Washington Redskins1-3-4.5-13.7-18.2
32Jacksonville Jaguars0-3-22.3-14.4-36.8
• You won’t be too surprised to see the Bengals atop the ratings. But you might be surprised to see the 2-1 Ravens up at #2 on the list. Then again, Baltimore lost a close game to Cincinnati, beat Pittsburgh by 20, and beat a Cleveland team that checks in at #8.
• Wait, why is Cleveland #8? Well, the Browns have played the Ravens, Steelers, and Saints, and have a points differential of just -3.1 That’s pretty good, considering Baltimore is #2, Pittsburgh is #6, and New Orleans is #11.
• Wait, the Steelers are #6? Well, Pittsburgh doesn’t get dinged for losing badly to Baltimore, because the Ravens are the 2nd ranked team. Essentially, the SRS says in order to make the ratings converge, we need to set the Bengals’ rating at a really high number.  And since Baltimore only bad game was against the Bengals, we need to give the Ravens a really high rating, which means Pittsburgh can lose by 20 to the Ravens and still check in as well above average. What really helps is that the Steelers blew out #14 Carolina in Carolina. Since Baltimore, Pittsburgh, and Cleveland are so connected, that game matters a lot. In fact, here is how all AFC North teams have done in non-division games this year:
• Pittsburgh beat #14 Carolina on the road by 18
• Cleveland beat #11 New Orleans at home by 2
• Cincinnati beat #5 Atlanta by 14 at home
• Cincinnati beat #18 Tennessee by 26 at home2
• Let that sink in for a minute: the AFC North is 4-0 in inter-divisional games this year, with the four wins coming by an average of 15 points again pretty decent teams. That’s how they have four of the top eight teams in the SRS.
• Things like the Browns being very good makes the Saints look a lot better. In fact, New Orleans posted its worst game of the year by SRS standards in its lone win. New Orleans gets an SRS of +10 for playing to a 2-point loss in Cleveland, a +8.5 for losing by three in Atlanta, and only +2.1 for beating Minnesota at home by 11 points.
• In non-AFC North news, the thing that really stands out is Philadelphia’s 27th-place rating. So what gives? Jacksonville is horrible — the SRS puts them at 36.8 points below average — and the Eagles only beat them by 17 points at home. For reference, Jacksonville lost its other two games by 27 (at home) and 31 (on the road) points. The Eagles are also penalized for barely beating Washington. And Washington is terrible according to the SRS, ranking 31st courtesy of losing badly to the Giants, beating Jacksonville, and losing by 11 in Houston (the #22 team) in its non-Eagles games.
• What about that Colts win? Well, Indianapolis is only 26th in the ratings; after all, the Colts only beat Jacksonville, which doesn’t mean anything.  And in the team’s only other non-Eagles game, Indianapolis lost to Denver. But that doesn’t help much because the Broncos are only 17th. Why is that? Well, Denver won by 7 at home against a bad Chiefs team and lost by 6 on the road to a good Seahawks team. In other words, the SRS doesn’t know how good Denver is.  Had Denver blown out Kansas City, that would really have helped the ratings of Denver, Indianapolis, and Philadelphia, but instead, that game is dragging down the scores of all three teams.

The best way to learn about a team’s rating on the season is to see its single game ratings. To make that easy, I’ve included each team’s rating from each game in the table below. You can search for any team by using the search box. Here’s how to read the table if you type “Jets” into the search box. New York’s best game came in a 27-19 loss at home to Chicago, which provides a MOV of -11. Since the Bears are 7.4 points above average, the Jets get a rating of -3.6 for that game.

W#TeamH/ROppPFPAWinMOVSOSSRS
1Cincinnati Bengals@Baltimore Ravens2316Win1022.232.2
2Baltimore RavensPittsburgh Steelers266Win171532
2Cincinnati BengalsAtlanta Falcons2410Win1115.526.5
3Cincinnati BengalsTennessee Titans337Win23.50.423.9
3San Diego Chargers@Buffalo Bills2210Win158.523.5
3Pittsburgh Steelers@Carolina Panthers3719Win211.822.8
2Dallas Cowboys@Tennessee Titans2610Win190.419.4
2New England Patriots@Minnesota Vikings307Win25-5.919.1
1Arizona CardinalsSan Diego Chargers1817Win019.119.1
1Detroit LionsNew York Giants3514Win180.618.6
2Chicago Bears@San Francisco 49ers2820Win116.817.8
2Carolina PanthersDetroit Lions247Win143.717.7
1Baltimore RavensCincinnati Bengals1623Loss-1027.517.5
3Baltimore Ravens@Cleveland Browns2321Win71017
1Pittsburgh SteelersCleveland Browns3027Win71017
2Atlanta Falcons@Cincinnati Bengals1024Loss-1127.516.5
3Atlanta FalconsTampa Bay Buccaneers5614Win31.5-15.316.2
1San Diego Chargers@Arizona Cardinals1718Loss015.815.8
3Cleveland BrownsBaltimore Ravens2123Loss-722.215.2
1San Francisco 49ers@Dallas Cowboys2817Win141.115.1
1Tennessee Titans@Kansas City Chiefs2610Win19-415
2Arizona Cardinals@New York Giants2514Win140.614.6
1Buffalo Bills@Chicago Bears2320Win77.414.4
1Atlanta FalconsNew Orleans Saints3734Win76.913.9
3Arizona CardinalsSan Francisco 49ers2314Win76.813.8
3Kansas City Chiefs@Miami Dolphins3415Win22-8.913.1
1Seattle SeahawksGreen Bay Packers3616Win17-4.212.8
2Seattle Seahawks@San Diego Chargers2130Loss-719.112.1
1Minnesota Vikings@St. Louis Rams346Win27.5-15.911.6
4New York Giants@Washington Redskins4514Win29-18.210.8
2New Orleans Saints@Cleveland Browns2426Loss01010
3San Francisco 49ers@Arizona Cardinals1423Loss-715.88.8
1New Orleans Saints@Atlanta Falcons3437Loss-715.58.5
1Cleveland Browns@Pittsburgh Steelers2730Loss-7158
3Seattle SeahawksDenver Broncos2620Win70.67.6
2Buffalo BillsMiami Dolphins2910Win16-8.97.1
2Cleveland BrownsNew Orleans Saints2624Win06.96.9
1Miami DolphinsNew England Patriots3320Win10-3.16.9
2Pittsburgh Steelers@Baltimore Ravens626Loss-1722.25.2
3Detroit LionsGreen Bay Packers197Win9-4.24.8
3New York GiantsHouston Texans3017Win10-5.84.2
3Buffalo BillsSan Diego Chargers1022Loss-1519.14.1
3Tennessee Titans@Cincinnati Bengals733Loss-23.527.54
3Denver Broncos@Seattle Seahawks2026Loss-710.83.8
2Denver BroncosKansas City Chiefs2417Win7-43
3Chicago Bears@New York Jets2719Win11-8.22.8
2Houston Texans@Oakland Raiders3014Win19-16.72.3
3New Orleans SaintsMinnesota Vikings209Win8-5.92.1
2New York GiantsArizona Cardinals1425Loss-1415.81.8
1Chicago BearsBuffalo Bills2023Loss-78.51.5
3Minnesota Vikings@New Orleans Saints920Loss-86.9-1.1
2Green Bay PackersNew York Jets3124Win7-8.2-1.2
2San Francisco 49ersChicago Bears2028Loss-117.4-3.6
3New York JetsChicago Bears1927Loss-117.4-3.6
1Denver BroncosIndianapolis Colts3124Win7-12.1-5.1
3Green Bay Packers@Detroit Lions719Loss-93.7-5.3
3St. Louis RamsDallas Cowboys3134Loss-71.1-5.9
3Carolina PanthersPittsburgh Steelers1937Loss-2115-6
1Green Bay Packers@Seattle Seahawks1636Loss-1710.8-6.2
1Carolina Panthers@Tampa Bay Buccaneers2014Win9-15.3-6.3
1Indianapolis Colts@Denver Broncos2431Loss-70.6-6.4
2Kansas City Chiefs@Denver Broncos1724Loss-70.6-6.4
1Tampa Bay BuccaneersCarolina Panthers1420Loss-91.8-7.2
1Dallas CowboysSan Francisco 49ers1728Loss-146.8-7.2
2Miami Dolphins@Buffalo Bills1029Loss-168.5-7.5
2St. Louis Rams@Tampa Bay Buccaneers1917Win7-15.3-8.3
3Dallas Cowboys@St. Louis Rams3431Win7-15.9-8.9
3Houston Texans@New York Giants1730Loss-100.6-9.4
3New England PatriotsOakland Raiders169Win7-16.7-9.7
1New York JetsOakland Raiders1914Win7-16.7-9.7
3Indianapolis Colts@Jacksonville Jaguars4417Win27-36.8-9.8
3Oakland Raiders@New England Patriots916Loss-7-3.1-10.1
1Houston TexansWashington Redskins176Win8-18.2-10.2
2Washington RedskinsJacksonville Jaguars4110Win26-36.8-10.8
2New York Jets@Green Bay Packers2431Loss-7-4.2-11.2
2Detroit Lions@Carolina Panthers724Loss-141.8-12.2
1Washington Redskins@Houston Texans617Loss-8-5.8-13.8
1New York Giants@Detroit Lions1435Loss-183.7-14.3
1Oakland Raiders@New York Jets1419Loss-7-8.2-15.2
3Tampa Bay Buccaneers@Atlanta Falcons1456Loss-31.515.5-16
2Tennessee TitansDallas Cowboys1026Loss-191.1-17.9
1Kansas City ChiefsTennessee Titans1026Loss-190.4-18.6
1New England Patriots@Miami Dolphins2033Loss-10-8.9-18.9
2Oakland RaidersHouston Texans1430Loss-19-5.8-24.8
3Miami DolphinsKansas City Chiefs1534Loss-22-4-26
2Minnesota VikingsNew England Patriots730Loss-25-3.1-28.1
4Washington RedskinsNew York Giants1445Loss-290.6-28.4
1St. Louis RamsMinnesota Vikings634Loss-27.5-5.9-33.4
3Jacksonville JaguarsIndianapolis Colts1744Loss-27-12.1-39.1
2Jacksonville Jaguars@Washington Redskins1041Loss-26-18.2-44.2
1. Actually, they’re even more harmed in the SRS, where that points differential turns into -14. []
2. The Ravens have not played a non-divisional road game this year. []
• George

I’m glad that you posted this up, as where I’ve started to looking at adding other things into my model (individual HFA, home and away random error), I worked out my first set of numbers through Thursday night’s game and didn’t like what I came out with (but they are generally going in the same direction as yours).

I have some freak results, where teams have only played one or two games at home (or away) and where I have two variables for home games now due to the small sample size (e.g. I have Jacksonville, ranked 18th at home, yet 32nd away). E.g. point that I was making re: HFA – average HFA I have at 0.86 at the moment, with a high of 21.06 (Houston) and a low of -36.68 (Minnesota) – don’t think that there is enough data there yet to draw solid conclusions and expect that these are outliers.

Ratings are below: First number is a home rating, second number is an away rating (apologies for forgetting how to format the text into a table);

TEAM HOME RATING AWAY RATING
Arizona 13.91 20.72
Atlanta 26.78 12.40
Baltimore 31.75 27.22
Buffalo 0.33 -2.24
Carolina -6.82 -18.11
Chicago -4.71 -5.71
Cincinnati 26.94 38.24
Cleveland 25.76 18.80
Dallas -6.65 -18.70
Denver 30.55 12.21
Detroit 10.74 -24.35
Green Bay 11.98 -1.80
Houston -0.21 -3.30
Indianapolis -4.96 23.03
Jacksonville -3.44 -24.67
Kansas City -15.02 23.02
Miami 3.98 -18.59
Minnesota -32.01 6.30
New England -11.23 -8.95
New Orleans 17.24 23.24
NY Giants 9.65 -10.79
NY Jets -13.19 4.43
Oakland -19.36 -18.15
Pittsburgh 22.87 10.66
San Diego 14.10 12.39
San Francisco -13.76 4.40
Seattle 18.15 5.16
St. Louis -21.17 -22.11
Tampa Bay -23.59 -15.74
Tennessee -34.17 0.43
Washington 6.85 -11.16

• Chase Stuart

Here are the division power ratings; i.e., ratings for all teams in the division in inter-division games.

```Division.....G..Win..Rec...Win%....MOV....SOS....SRS
AFC-North....4...4...4-0...1.00...13.9....6.2...20.0
NFC-West....10...6...6-4...0.60....0.7....2.3....3.0
NFC-South....6...2...2-4...0.33...-2.8....5.8....2.9
NFC-North...10...5...5-5...0.50....0.4....0.0....0.4
AFC-West....10...4...4-6...0.40...-0.8....0.8....0.0
AFC-East.....8...4...4-4...0.50...-1.1...-1.7...-2.8
NFC-East....10...6...6-4...0.60....2.9...-8.6...-5.7
AFC-South...10...3...3-7...0.30...-6.1...-5.3..-11.4
```
• Chase Stuart

Here are the standard deviations:

```StDevRk...StDev...Team
1...1.4...Atlanta Falcons
2...2.7...Green Bay Packers
3...2.8...Seattle Seahawks
4...2.8...Arizona Cardinals
5...4...San Diego Chargers
6...4...New York Jets
7...4.2...New Orleans Saints
8...4.2...Cincinnati Bengals
9...4.5...Cleveland Browns
10...4.9...Denver Broncos
11...5.3...Buffalo Bills
12...7...Houston Texans
13...7.1...Indianapolis Colts
14...7.4...Oakland Raiders
15...7.8...Washington Redskins
16...7.9...Tampa Bay Buccaneers
17...8.5...Baltimore Ravens
18...8.8...Jacksonville Jaguars
19...9...Pittsburgh Steelers
21...9...Chicago Bears
22...9.5...San Francisco 49ers
23...10.6...New York Giants
24...13.8...Carolina Panthers
25...15.2...St. Louis Rams
26...15.4...Detroit Lions
27...15.9...Dallas Cowboys
28...16...Kansas City Chiefs
29...16.5...Miami Dolphins
30...16.8...Tennessee Titans
31...19.8...New England Patriots
32...20.3...Minnesota Vikings
```

Minnesota had one blowout, one got blowed out, and one average game. New England looked great against Minnesota, and then bad and really bad against the Raiders and Dolphins. Meanwhile, Atlanta has been insanely consistent after adjusting for SOS, which is weird since they had one monster blowout, one loss, and one game that they won in overtime. Alas, SOS adjustments matter.