The Other Dungy Index

Tony Dungy’s teams haven’t fared particularly well, relative to expectations, in postseason games. So when, in my last post, I created a metric to measure such performance, I named it after the man. That was something of a cheap shot.

I’ll right that wrong here by noting that Dungy has a superlative record of producing and maintaining very good teams. In his four years at the helm of the Colts, they’ve won 48 games. Since 1990, only three teams have bettered that number during a four-year stretch and three more have equalled it. Yeah, I know, he inherited Peyton, Edge, and Marvin. He also inherited a defense that was a complete wreck. To average 12 wins a year over a four-year span is remarkable under any circumstances.

Let’s now examine the fraud known as Bill Parcells. He seems to get lots of credit for turning losers into winners. Most recently, he took over a Cowboy team that had been dreadful for several years prior to his arrival. Immediately, they were contenders in the NFC. There was a bump in the road the following year, but the Cowboys were once again in the playoff mix in 2005.

But what has he done, really? In the three years prior to Parcells’ arrival, the Cowboys were 15-33. That’s pretty bad. In the three years since, they’ve been 25-23. Better. Is that Parcells, or is that just what bad teams naturally do in the NFL these days: get better? Since 1990, there have been 35 teams that won between 14 and 16 games over a three-year span. These teams, as a group, would have to be considered similar to the Cowboy team that Parcells took inherited. Their performance during the next three years could serve as a yardstick against which to measure Parcells’ performance. During the next three years, the other comparably bad teams averaged 22 wins and 0.85 playoff appearances. Bill has notched 25 wins and one playoff appearance. Solid effort? Yes. Miraculous turnaround? No.

For various reasons — some “natural” and some due to NFL tinkering — teams with good records tend to regress while teams with bad records tend to get better. That’s a fact that will surprise very few readers of this blog, I’m sure. But it’s at the heart of why I believe Dungy has a more impressive record than Parcells — than just about anyone — over the last few years. His teams, despite being good, have not regressed. During their most recent stints, Parcells has been aided by the forces of nature while Dungy has been fighting against them.

On the other hand, even someone like myself who possesses a deep and irrational hatred of Parcells would acknowledge that Dungy did inherit a better team than Parcells did. It would therefore be unfair to simply compare their records.

I want to quantify these ideas a bit. The first step is to establish a baseline. If a team won X games in 2005, how many games should they be expected to win in 2006? Regression can provide us with an estimated answer. A plain old linear regression including all teams since 1990 produces the following formula:


Next Year Wins =~ 5.51 + .317 * LastYearWins

Some quick checks indicate that it passes the smell test: plug in 8 and you get out 8, plug in 12 and you get out 9.3. Teams since 1990 that have won twelve games have actually averaged about 9.2 wins the next year. The formula models reality fairly well (not surprising, of course, since it was built to fit reality).

But this same formula doesn’t model the reality of 1973 or 1985 very well. Those were different times, so they require different formulas. I simply ran a separate regression for each of the three time periods 1970–1979, 1980–1989, and 1990–present. I’ve got no good reason for selecting those cutoff points. Probably 1978 (a bunch of rule changes) and 1993 (free agency) would be better cutoffs. Even better, I could ask J.C. to tell me about some statistical whizbangery that would examine the data and tell me the best place to draw the cutoffs. But I’m lazy, so nominal decades it is.

The next step is to go through each coach’s record, year by year, and compare his expected wins to his actual wins. Here, for example, is Dungy:

         Expected  Actual
Year Team  wins     wins    Diff
---------------------------------
1996  tam   7.7      6.0    -1.7
1997  tam   7.4     10.0     2.6
1998  tam   8.7      8.0    -0.7
1999  tam   8.0     11.0     3.0
2000  tam   9.0     10.0     1.0
2001  tam   8.7      9.0     0.3
2002  ind   7.4     10.0     2.6
2003  ind   8.7     12.0     3.3
2004  ind   9.3     12.0     2.7
2005  ind   9.3     14.0     4.7

That’s about 84 expected wins and 102 actual wins, making +18 marginal wins. He gets some credit for turning around a bad Bucs team. But he scores most of his points by keeping his teams at (or near) the top of the league consistently.

Before we get to the full list, a couple of technical notes are in order:

1. Only seasons since the 1970 merger are counted. Guys like Don Shula, whose career started before 1970, are included but the games prior to 1970 are ignored. These guys are asterisked.

2. I didn’t want to order the list by Total Marginal Wins because that would weight long careers too heavily. Ordering the list by Marginal Wins per season, on the other hand, wouldn’t give enough weight to long successful careers. So I ordered the list by (an approximation of) the probability that chance would produce the given record or a better one.

                  Expected  Actual    Marginal
                     wins    wins       wins
---------------------------------------------
*Don Shula            239     276      +36.5
 Joe Gibbs            123     147      +23.6
 Tony Dungy            84     102      +17.7
 Mike Holmgren        117     138      +20.9
 Marty Schottenheimer 159     183      +24.3
 Bill Cowher          121     142      +20.8
 Mike Shanahan        109     129      +19.8
 George Seifert        97     114      +16.7
 Bill Parcells        143     164      +20.9
 Bill Walsh            83      96      +13.2
 Andy Reid             60      70      +10.2
*Tom Landry           183     200      +16.5
*George Allen          77      88      +10.7
*Chuck Noll           191     208      +17.7
 Marv Levy            129     144      +14.6
*John Madden           95     106      +10.8
 Jon Gruden            65      73       +8.3
*Bud Grant            141     152      +11.3
 John Fox              30      36       +5.7
 Jimmy Johnson         71      80       +8.6
*Paul Brown            48      55       +6.9
 Marvin Lewis          22      27       +4.8
 Chuck Knox           185     198      +12.9
 Bill Belichick        91      99       +8.3
 Tom Coughlin          78      85       +7.1
 Chuck Fairbanks       46      51       +5.3
 Art Shell             42      47       +4.9
 Bobby Ross            72      78       +6.2
 Dennis Green         101     108       +7.0
 Mike Sherman          52      57       +4.6
 Jack Del Rio          23      26       +3.1
 Barry Switzer         37      40       +3.4
 Jeff Fisher           90      96       +5.6
 Dick Vermeil         117     124       +6.4
 Wade Phillips         41      45       +3.5
 Mike Martz            53      57       +3.7
 Mike Ditka           119     124       +5.5
 Don Coryell          112     117       +5.3
 Red Miller            39      42       +2.9
 Brian Billick         58      62       +3.8
 John Ralston          38      41       +3.0
 Dan Reeves           189     195       +6.2
 Jerry Burns           50      53       +2.9
 Jim Mora             123     127       +4.2
 Walt Michaels         42      45       +2.4
 Bum Phillips          86      89       +3.1
*Joe Schmidt           28      30       +1.6
 John Robinson         74      75       +1.6
 Mike Tice             31      32       +1.1
 John Mackovic         29      30       +1.0
 Raymond Berry         44      45       +0.8
*Charley Winner        21      21       +0.6
 Jim Fassel            58      58       +0.8
 Tom Flores           103     104       +0.8
 Jack Pardee           90      91       +0.7
 Wayne Fontes          64      64       +0.5
 Steve Mariucci        73      73       +0.3
 Buddy Ryan            56      56       +0.1
 Ron Meyer             60      60       +0.1
 Jerry Glanville       61      61       +0.0
 Forrest Gregg         84      84       -0.2
 Ted Marchibroda       92      92       -0.4
 Dan Devine            32      31       -0.7
*Nick Skorich          36      35       -0.7
 Pete Carroll          34      33       -1.1
 Rick Forzano          24      23       -1.0
 Tommy Prothro         51      49       -1.7
 Sam Rutigliano        56      54       -1.8
 Don McCafferty        39      38       -1.4
 Jack Patera           45      43       -2.2
 Jim Haslett           47      45       -2.3
 Jim Hanifan           46      43       -2.5
 Herman Edwards        41      39       -2.5
 Dick Jauron           38      35       -2.7
 Monte Clark           59      56       -3.6
*Lou Saban             52      49       -3.5
 Dave Wannstedt        89      85       -4.5
*Dick Nolan            71      66       -4.2
 Joe Walton            58      54       -4.0
 Neill Armstrong       33      30       -3.3
*Ray Malavasi          45      42       -3.7
 Leeman Bennett        60      55       -4.7
*Norm VanBrocklin      40      36       -3.9
 Bart Starr            65      60       -5.3
*Hank Stram            58      53       -4.9
 Ray Rhodes            42      38       -4.2
 Gene Stallings        28      24       -4.5
 Butch Davis           30      25       -4.6
*Alex Webster          32      27       -4.7
 John McKay            56      49       -7.1
 Sam Wyche             93      84       -8.3
 Norv Turner           67      60       -7.7
 June Jones            24      19       -4.5
 Ray Perkins           54      46       -7.7
 John North            19      14       -4.8
 Bill Johnson          29      25       -4.9
 Mike McCormack        34      28       -6.5
 Bill Arnsparger       17      11       -5.1
 Dave McGinnis         21      16       -5.3
 Dennis Erickson       48      40       -7.6
 Gregg Williams        23      17       -5.6
 Dom Capers            57      48       -9.4
 Darryl Rogers         27      20       -6.8
 Rich Kotite           48      40       -8.3
 Frank Kush            18      12       -5.9
 Abe Gibron            19      13       -6.1
 Ron Erhardt           27      21       -6.1
 Vince Tobin           37      29       -8.1
 David Shula           34      26       -8.2
 Paul Wiggin           20      14       -6.5
*Weeb Ewbank           32      24       -7.5
 Mike Riley            21      14       -7.0
 Lindy Infante         46      36      -10.1
 Dave Campo            22      15       -7.2
 Dan Henning           50      38      -11.8
 Marion Campbell       53      39      -13.8
 Bruce Coslet          58      44      -14.0
 Joe Bugel             35      24      -11.5
 Kay Stephenson        21      12       -8.9
 Ed Biles              22      11      -11.3

How you weight the relative importance of regular season performance versus postseason performance is up to you. But either way, it’s tough to come up with a better candidate for best post-Merger NFL coach than Joe Gibbs.

5 Responses “The Other Dungy Index”

  1. Ahem. Is that a fraud I see in the number 9 slot?

  2. Vince says:

    Am I the only person who skipped the top guys to see who was at the bottom of the list? And what does that say about me?

  3. e says:

    Abe Gibron -6.1
    Jack Pardee +0.7
    Neill Armstrong -3.3
    Mike Ditka +5.5
    Dave Wannstedt -4.5
    Dick Jauron -2.7

    [ dissolve to the Round Table, where Bill Swerski and his Chicago Bears Super Fan friends sit, surroundsed by polish sausange and bratwurst ]

    Bill Swerski: Good afternoon, my friends, and welcome to “Bill Swerski’s Super Fans”! I’m Bill Swerski, and with me, as always, are the Super Fans: Pat Arnold..

    Bill Swerski: Now, gentlemen, let me ask you this: What if Da Bears were all 14 inches tall, you know, about so high? Now, what’s your score of today’s game?

    Carl Wollarski: Against Da Giants?

    Bill Swerski: Yes, give ‘em a handicap.

    Carl Wollarski: Bears 18, Giants 10. And that would finally be a good game.

    Pat Arnold: Yeah, it would be a good game. Mini Bears 24, Giants 14.

    Todd O’Conner: What about Ditka? Would he be mini, too?

    Bill Swerski: No, he would be full-grown.

    Todd O’Conner: Oh, then, uh.. Mini Bears 31, Giants 7.

    Carl Wollarski: Oh, hold on. Then I change mine, too. I thought it was Mini Ditka.

    Bill Swerski: Okay, gentlemen, another scenario: Da Bears, they don’t make it, the plane is delayed.. and the only one who shows up is Ditka. Ditka vs. Da Giants. Okay, score, gentlemen.

    Pat Arnold: Alright, after da heart attack, I gotta say Ditka 17, Giants 14. He just barely gets by.

    Bill Swerski: Alright, that sounds exciting. Perhaps, you know, a late Ditka field goal.

    Todd O’Conner: Bears!

    Superfans: Bears!!

  4. Why not divide actual wins by expected wins to obtain a percentage, rather than deploy longevity as the primary ranking arbiter? In fact, Dungy vaults to number one by this method, with a score of 121.43 over 100, or + 21.43%.

Trackbacks/Pingbacks

  1. […] about these numbers, including the zany formula they used to come up with projected wins, here and here. Posted in Marty […]