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Predicting the Lions: 1980-Now

grandy

grandy

Senior Member
Joined
Aug 4, 2011
Messages
11,699
The Grantland article KC posted had me intrigued, so I went through the Lions history and applied the same formula for the last 30 or so years.

http://grantland.com/features/nfl-stats-predicting-success/
http://grantland.com/features/breaking-best-nfl-stats/

Pyth Diff = Pythagorean Differential, expected winning percentage based on points for and points against (ex. +1 means 1 win better than expected, -1 means 1 win worse than expected)
1TD Record = Record in games decided by 7 points or less
TO Margin = Defensive Turnovers - Offensive Turnovers

1980
Actual Record: 9-7 (.563)
Pyth Diff: -0.9
1TD Record: 1-4
TO Margin: +3

1981
Prediction: Slight Improvement
Actual Record: 8-8 (.500)
Pyth Diff: -1.9
1TD Record: 3-6
TO Margin: -4
Actual: Very Slight Decline (-1 win)

1982
Precition: Improvement
Actual Record: 4-5 (.444) (strike shortened)
Pyth Diff: -1.2
1TD Record: 3-4
TO Margin: 0
Actual: Very Slight Decline, but difficult to tell with short season

1983
Prediction: Slight Improvement
Actual Record: 9-7 (.563)
Pyth Diff: -0.8
1TD Record: 3-2
TO Margin: -2
Actual: Slight Improvement

1984
Prediction: About the same
Actual Record: 4-11-1 (.281)
Pyth Diff: -0.2
1TD Record: 4-4-1
TO Margin: -11
Actual: Big Decline (-4.5 wins)

1985
Prediction: About the same, maybe slightly better
Actual Record: 7-9 (.438)
Pyth Diff: +0.6
1TD Record: 3-3
TO Margin: -5
Actual: Improvement (+2.5 wins)

1986
Prediction: About the same
Actual Record: 5-11 (.313)
Pyth Diff: -1.5
1TD Record: 3-7
TO Margin: +4
Actual: Slight Decline (-2 wins)

1987
Prediction: Improvement
Actual Record: 4-11 (.267) (strike shortened)
Pyth Diff: -0.5
1TD Record: 1-5
TO Margin: -5
Actual: Very Slight Decline

1988
Prediction: Slight Improvement
Actual Record: 4-12 (.250)
Pyth Diff: -0.8
1TD Record: 1-6
TO Margin: +3
Actual: Very Slight Decline

1989
Prediction: Improvement
Actual Record: 7-9 (.438)
Pyth Diff: +0.4
1TD Record: 4-4
TO Margin: -16
Actual: Improvement (+3 wins)

1990
Prediction: Slight Improvement
Actual Record: 6-10 (.375)
Pyth Diff: -1.0
1TD Record: 3-5
TO Margin: -1
Actual: Very Slight Decline (-1 win)

1991
Prediction: Slight Improvement
Actual Record: 12-4 (.750)
Pyth Diff: +2.7
1TD Record: 4-0
TO Margin: +6
Actual: Huge Improvement (+6 wins)

1992
Prediction: Decline
Actual Record: 5-11 (.313)
Pyth Diff: -1.2
1TD Record: 1-6
TO Margin: -4
Actual: Huge Decline (-7 wins)

1993
Prediction: Improvement
Actual Record: 10-6 (.625)
Pyth Diff: +1.8
1TD Record: 5-1
TO Margin: +3
Actual: Huge Improvement (+6 wins)

1994
Prediction: Decline
Actual Record: 9-7 (.563)
Pyth Diff: +0.6
1TD Record: 6-4
TO Margin: -1
Actual: Very Slight Decline (-1 win)

1995
Prediction: About the same, maybe slightly worse
Actual Record: 10-6 (.625)
Pyth Diff: -0.4
1TD Record: 4-3
TO Margin: +10
Actual: Very Slight Improvement (+1 win)

1996
Prediction: About the same, maybe slightly worse
Actual Record: 5-11 (.313)
Pyth Diff: -1.2
1TD Record: 2-5
TO Margin: -7
Actual: Big Decline (-5 wins)

1997
Prediction: Improvement
Actual Record: 9-7 (.563)
Pyth Diff: -1.0
1TD Record: 2-3
TO Margin: -3
Actual: Improvement (+4 wins)

1998
Prediction: Slight Improvement
Actual Record: 5-11 (.313)
Pyth Diff: -1.0
1TD Record: 3-5
TO Margin: -4
Actual: Decline (-4 wins)

1999
Prediction: Slight Improvement
Actual Record: 8-8 (.500)
Pyth Diff: 0.0
1TD Record: 3-3
TO Margin: +10
Actual: Improvement (+3 wins)

2000
Prediction: About the same, maybe slightly worse
Actual Record: 9-7 (.563)
Pyth Diff: +1.0
1TD Record: 6-3
TO Margin: +11
Actual: Very Slight Increase (+1 win)

2001
Prediction: Decline
Actual Record: 2-14 (.125)
Pyth Diff: -2.1
1TD Record: 2-8
TO Margin: -16
Actual: Huge Decline (-7 wins)

2002
Prediction: Big Improvement
Actual Record: 3-13 (.188)
Pyth Diff: -1.6
1TD Record: 3-7
TO Margin: -7
Actual: Very Slight Improvement (+1 win)

2003
Prediction: Improvement
Actual Record: 5-11 (.313)
Pyth Diff: +0.1
1TD Record: 1-4
TO Margin: 0
Actual: Slight Improvement (+2 wins)

2004
Prediction: About the same, maybe slightly better
Actual Record: 6-10 (.375)
Pyth Diff: -0.4
1TD Record: 3-6
TO Margin: +4
Actual: Very Slight Improvement (+1 win)

2005
Prediction: About the same, maybe slightly better
Actual Record: 5-11 (.313)
Pyth Diff: -0.2
1TD Record: 2-5
TO Margin: +1
Actual: Very Slight Decline (-1 win)

2006
Prediction: About the same, maybe slightly better
Actual Record: 3-13 (.188)
Pyth Diff: -2.6
1TD Record: 1-8
TO Margin: -9
Actual: Slight Decline (-2 wins)

2007
Prediction: Big Improvement
Actual Record: 7-9 (.438)
Pyth Diff: +1.3
1TD Record: 3-2
TO Margin: -1
Actual: Improvement (+4 wins)

2008
Prediction: Decline
Actual Record: 0-16 (.000)
Pyth Diff: -2.8
1TD Record: 0-5
TO Margin: -9
Actual: Huge Decline (-7 wins)

2009
Prediction: Big Improvement
Actual Record: 2-14 (.125)
Pyth Diff: -0.9
1TD Record: 2-2
TO Margin: -18
Actual: Slight Improvement (+2 wins)

2010
Prediction: Improvement
Actual Record: 6-10 (.375)
Pyth Diff: -1.8
1TD Record: 4-6
TO Margin: +4
Actual: Improvement (+4 wins)

2011
Prediction: Improvement
Actual Record: 10-6 (.625)
Pyth Diff: +0.1
1TD Record: 4-3
TO Margin: +11
Actual: Improvement (+4 wins)

2012
Prediction: Slight Decline
Actual Record: 4-12 (.250)
Pyth Diff: -2.5
1TD Record: 3-8
TO Margin: -16
Actual: Huge Decline (-6 wins)

2013
Prediction: Big Improvement
Actual Record: 7-9 (.438)
Pyth Diff: -1.5
1TD Record: 3-6
TO Margin: -12
Actual: Improvement (+3 wins)

2014
Prediction: Improvement
Actual Record: ???
Pyth Diff: ???
1TD Record: ???
TO Margin: ???
Actual: ???

By taking a a look at the expected and actual W/L from the previous year and predicting the following year based off that I gather that the accuracy of the predictions were...

Accurate Predictions: 1981, 1983, 1989, 1992, 1993, 1994, 1997, 1999, 2000, 2001, 2003, 2004, 2006, 2007, 2008, 2010, 2011, 2013
In the middle somewhere: 1985, 1986, 1988, 1990, 1991, 1995, 2002, 2005, 2009, 2012
Inaccurate Predictions: 1984, 1987, 1996, 1998
N/A: 1982

I'm not pleased with the prediction terminology I used, but I didn't want to spend any more time than necessary on this post.
 
Last edited:
grandy said:
The Grantland article KC posted had me intrigued, so I went through the Lions history and applied the same formula for the last 30 or so years.

http://grantland.com/features/nfl-stats-predicting-success/
http://grantland.com/features/breaking-best-nfl-stats/

Pyth Diff = Pythagorean Differential, expected winning percentage based on points for and points against (ex. +1 means 1 win better than expected, -1 means 1 win worse than expected)
1TD Record = Record in games decided by 7 points or less
TO Margin = Defensive Turnovers - Offensive Turnovers

1980
Actual Record: 9-7 (.563)
Pyth Diff: -0.9
1TD Record: 1-4
TO Margin: +3

1981
Prediction: Slight Improvement
Actual Record: 8-8 (.500)
Pyth Diff: -1.9
1TD Record: 3-6
TO Margin: -4
Actual: Very Slight Decline (-1 win)

1982
Precition: Improvement
Actual Record: 4-5 (.444) (strike shortened)
Pyth Diff: -1.2
1TD Record: 3-4
TO Margin: 0
Actual: Very Slight Decline, but difficult to tell with short season

1983
Prediction: Slight Improvement
Actual Record: 9-7 (.563)
Pyth Diff: -0.8
1TD Record: 3-2
TO Margin: -2
Actual: Slight Improvement

1984
Prediction: About the same
Actual Record: 4-11-1 (.281)
Pyth Diff: -0.2
1TD Record: 4-4-1
TO Margin: -11
Actual: Big Decline (-4.5 wins)

1985
Prediction: About the same, maybe slightly better
Actual Record: 7-9 (.438)
Pyth Diff: +0.6
1TD Record: 3-3
TO Margin: -5
Actual: Improvement (+2.5 wins)

1986
Prediction: About the same
Actual Record: 5-11 (.313)
Pyth Diff: -1.5
1TD Record: 3-7
TO Margin: +4
Actual: Slight Decline (-2 wins)

1987
Prediction: Improvement
Actual Record: 4-11 (.267) (strike shortened)
Pyth Diff: -0.5
1TD Record: 1-5
TO Margin: -5
Actual: Very Slight Decline

1988
Prediction: Slight Improvement
Actual Record: 4-12 (.250)
Pyth Diff: -0.8
1TD Record: 1-6
TO Margin: +3
Actual: Very Slight Decline

1989
Prediction: Improvement
Actual Record: 7-9 (.438)
Pyth Diff: +0.4
1TD Record: 4-4
TO Margin: -16
Actual: Improvement (+3 wins)

1990
Prediction: Slight Improvement
Actual Record: 6-10 (.375)
Pyth Diff: -1.0
1TD Record: 3-5
TO Margin: -1
Actual: Very Slight Decline (-1 win)

1991
Prediction: Slight Improvement
Actual Record: 12-4 (.750)
Pyth Diff: +2.7
1TD Record: 4-0
TO Margin: +6
Actual: Huge Improvement (+6 wins)

1992
Prediction: Decline
Actual Record: 5-11 (.313)
Pyth Diff: -1.2
1TD Record: 1-6
TO Margin: -4
Actual: Huge Decline (-7 wins)

1993
Prediction: Improvement
Actual Record: 10-6 (.625)
Pyth Diff: +1.8
1TD Record: 5-1
TO Margin: +3
Actual: Huge Improvement (+6 wins)

1994
Prediction: Decline
Actual Record: 9-7 (.563)
Pyth Diff: +0.6
1TD Record: 6-4
TO Margin: -1
Actual: Very Slight Decline (-1 win)

1995
Prediction: About the same, maybe slightly worse
Actual Record: 10-6 (.625)
Pyth Diff: -0.4
1TD Record: 4-3
TO Margin: +10
Actual: Very Slight Improvement (+1 win)

1996
Prediction: About the same, maybe slightly worse
Actual Record: 5-11 (.313)
Pyth Diff: -1.2
1TD Record: 2-5
TO Margin: -7
Actual: Big Decline (-5 wins)

1997
Prediction: Improvement
Actual Record: 9-7 (.563)
Pyth Diff: -1.0
1TD Record: 2-3
TO Margin: -3
Actual: Improvement (+4 wins)

1998
Prediction: Slight Improvement
Actual Record: 5-11 (.313)
Pyth Diff: -1.0
1TD Record: 3-5
TO Margin: -4
Actual: Decline (-4 wins)

1999
Prediction: Slight Improvement
Actual Record: 8-8 (.500)
Pyth Diff: 0.0
1TD Record: 3-3
TO Margin: +10
Actual: Improvement (+3 wins)

2000
Prediction: About the same, maybe slightly worse
Actual Record: 9-7 (.563)
Pyth Diff: +1.0
1TD Record: 6-3
TO Margin: +11
Actual: Very Slight Increase (+1 win)

2001
Prediction: Decline
Actual Record: 2-14 (.125)
Pyth Diff: -2.1
1TD Record: 2-8
TO Margin: -16
Actual: Huge Decline (-7 wins)

2002
Prediction: Big Improvement
Actual Record: 3-13 (.188)
Pyth Diff: -1.6
1TD Record: 3-7
TO Margin: -7
Actual: Very Slight Improvement (+1 win)

2003
Prediction: Improvement
Actual Record: 5-11 (.313)
Pyth Diff: +0.1
1TD Record: 1-4
TO Margin: 0
Actual: Slight Improvement (+2 wins)

2004
Prediction: About the same, maybe slightly better
Actual Record: 6-10 (.375)
Pyth Diff: -0.4
1TD Record: 3-6
TO Margin: +4
Actual: Very Slight Improvement (+1 win)

2005
Prediction: About the same, maybe slightly better
Actual Record: 5-11 (.313)
Pyth Diff: -0.2
1TD Record: 2-5
TO Margin: +1
Actual: Very Slight Decline (-1 win)

2006
Prediction: About the same, maybe slightly better
Actual Record: 3-13 (.188)
Pyth Diff: -2.6
1TD Record: 1-8
TO Margin: -9
Actual: Slight Decline (-2 wins)

2007
Prediction: Big Improvement
Actual Record: 7-9 (.438)
Pyth Diff: +1.3
1TD Record: 3-2
TO Margin: -1
Actual: Improvement (+4 wins)

2008
Prediction: Decline
Actual Record: 0-16 (.000)
Pyth Diff: -2.8
1TD Record: 0-5
TO Margin: -9
Actual: Huge Decline (-7 wins)

2009
Prediction: Big Improvement
Actual Record: 2-14 (.125)
Pyth Diff: -0.9
1TD Record: 2-2
TO Margin: -18
Actual: Slight Improvement (+2 wins)

2010
Prediction: Improvement
Actual Record: 6-10 (.375)
Pyth Diff: -1.8
1TD Record: 4-6
TO Margin: +4
Actual: Improvement (+4 wins)

2011
Prediction: Improvement
Actual Record: 10-6 (.625)
Pyth Diff: +0.1
1TD Record: 4-3
TO Margin: +11
Actual: Improvement (+4 wins)

2012
Prediction: Slight Decline
Actual Record: 4-12 (.250)
Pyth Diff: -2.5
1TD Record: 3-8
TO Margin: -16
Actual: Huge Decline (-6 wins)

2013
Prediction: Big Improvement
Actual Record: 7-9 (.438)
Pyth Diff: -1.5
1TD Record: 3-6
TO Margin: -12
Actual: Improvement (+3 wins)

2014
Prediction: Improvement
Actual Record: ???
Pyth Diff: ???
1TD Record: ???
TO Margin: ???
Actual: ???

By taking a a look at the expected and actual W/L from the previous year and predicting the following year based off that I gather that the accuracy of the predictions were...

Accurate Predictions: 1981, 1983, 1989, 1992, 1993, 1994, 1997, 1999, 2000, 2001, 2003, 2004, 2006, 2007, 2008, 2010, 2011, 2013
In the middle somewhere: 1985, 1986, 1988, 1990, 1991, 1995, 2002, 2005, 2009, 2012
Inaccurate Predictions: 1984, 1987, 1996, 1998
N/A: 1982

I'm not pleased with the prediction terminology I used, but I didn't want to spend any more time than necessary on this post.
Click to expand...

lol....you spent WAY more time than I would have! Interesting post though.
 
So Grantland formula is accurate and we should expect 10 wins. Sounds good
 
Just for fun, I checked the NFC North for 2013

Packers
Actual Record: 8-7-1 (.531)
Pyth Diff: +0.7
1TD Record: 4-4-1
TO Margin: -3
2014 Prediction: About the same

Bears
Actual Record: 8-8 (.500)
Pyth Diff: +0.7
1TD Record: 6-4
TO Margin: +5
2014 Prediction: Slight Decline

Lions
Actual Record: 7-9 (.438)
Pyth Diff: -1.5
1TD Record: 3-6
TO Margin: -12
2014 Prediction: Improvement

Vikings
Actual Record: 5-10-1 (.344)
Pyth Diff: -0.6
1TD Record: 4-4-1
TO Margin: -12
2014 Prediction: Slight Improvement
 
Grandy this is an awesome post. Thanks for this. This prediction method seems to only be able to predict slight improvement or decline with accuracy from my point of view, am I right? Every correct prediction is +- 1 or 2 wins. It can't predict major changes worth a crap. Is that a fair assessment?
 
LKP said:
So Grantland formula is accurate and we should expect 10 wins. Sounds good
Click to expand...

so grantland is saying since mayhew has been here were -31 in turnover margin and we lose a shiton of 1 td games every year.....nice job mayhew. Lastly were predicted to always improve since hes been here (except once).....but we don't.....nice job mayhew.
 
Last edited:
cheeno said:
Grandy this is an awesome post. Thanks for this. This prediction method seems to only be able to predict slight improvement or decline with accuracy from my point of view, am I right? Every correct prediction is +- 1 or 2 wins. It can't predict major changes worth a crap. Is that a fair assessment?
Click to expand...

the big flaw in this model is that it does not account for roster changes.
 
tomdalton22 said:
the big flaw in this model is that it does not account for roster changes.
Click to expand...

True, it's simply based off the team and statistics from the previous year. Assuming most of the team stays in tact, it could be a good indicator as to how the following season will turn out. Obviously injuries /big roster moves/great or terrible individual seasons can skew this.

I looked into the inaccurate years to see what might've happened. I've only been following the Lions for the last 15 years or so, somebody with a memory of these seasons might have to help.

1984 - Billy Sims injured halfway through the season
1987 - Chuck Long's first full season?
1996 - Scott Mitchell shit the bed after a solid 1995 season?
1998 - I know this was Barry's last season and it looks like the QB situation was unstable
 
Last edited:
mhughes0021 said:
so grantland is saying since mayhew has been here were -31 in turnover margin and we lose a shiton of 1 td games every year.....nice job mayhew. Lastly were predicted to always improve since hes been here (except once).....but we don't.....nice job mayhew.
Click to expand...

I'd say thats more coaching. -31 turnovers and we still are playing a ton of one TD games. Great job Mayhew. And I take out 2009 turnover margin. It was a Millen mess rebuild.
 
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