Newsgroups: rec.sport.football.pro
Subject: NFL_1992 Scoreboard: Predict/track NFL games
From: f67700241@violet.ccit.arizona.edu (Greg Franklin)
Date: 14 Dec 92 23:36:46 MST
Distribution: world,local
Organization: University of Arizona
Nntp-Posting-User: f67700241

At wuarchive.wustl.edu in the directory mirrors/win3/misc you will find
a file called nfl92.zip.  This is NFL_1992 Scoreboard, a Microsoft
Windows application that lets you predict and track NFL scores.  I have
been using it to post weekly reports on rec.sport.football.pro.

Here's a relevant excerpt from the docs.  Hopefully it will shed some
light on computer-based prediction algorithms.

[Begin excerpt]

NFL_1992 for Windows 3.x is owned and distributed by:

                            Thomas C. Kerr
                            5348 Black Oak
                           Fairfax, VA 22032


    NFL_1992 is a menu driven Windows 3.x application that allows you to
    predict, track, and update NFL football games.  The 1992 NFL game
    schedule per week is stored within the NFL_1992 data files.  The files
    also contain estimates of the offensive / defensive scoring strengths
    of each of the teams.  The initial offensive and defensive ratings for
    each team are based on the combined scores of all 1991 regular season
    and playoff games.  As the season wears on, and you use the program to
    enter 1992 pre-season and regular season games,  the ratings estimates
    and actual game scores are saved in TEAMS.DAT and GAMES.DAT every time
    you choose to update its databases.
    
    [...]

    The program is very simple to describe.   It's colorful, and it's fun.
    Playing with it sure beats mowing the grass on Sunday afternoon, or
    thinking about work I should've done this weekend.  I started running
    an early version of this program during the 1982 season - a Franklin
    1000, Apple Basic and a green 25x40 Elephant monitor.  MS-DOS, "C",
    and color windows certainly are more fun.

    Again, the program is very simple.  It processes game scores and
    maintains a simple, two parameter database on each team.  The data
    can be used to predict the outcome of next week's games.  Based on
    statistics, the program should predict 70% of the games correctly
    between now and infinity.  Typically, over the last nine seasons,
    the predictions have been pretty consistent in picking 9 to 10
    winners per week out of 14 games.   For three years, I tried some
    pretty sophisticated, numerical analysis techniques to improve the
    accuracy.   I tracked team performance, in terms of offensive and
    defensive ratings, as a function of whether the teams were on the
    road or at home.  I tried Dow-Jones type time series analysis -
    moving averages and weighted moving averages based on the last two
    weeks, three weeks,  four weeks ... nine weeks, etc.  By the time
    I was done, I had "successfully" lowered my prediction rate to low
    sixties.  The more complicated I made the model or the more parameters
    I added for model sophistication, the worse I did.  Finally, I gave
    up and went back to the two parameter model -- how does each team
    perform, offensively and defensively, relative to the average NFL
    team performance of 21 points scored per game.

    Over the course of a season, NFL teams average 21 points scored per
    game.  And typically, a team that puts 28 points on the board per
    week and limits the other guy to 14 points per week generally comes
    out ahead of the team that puts 14 points on the board while giving
    up 28 points.  In simple terms, that's the line taken by the predictions.

    When you stop and think about all the sophisticated statistics the
    commentators quote, they don't really do any better.  Average points
    scored on the road in the fourth quarter - percentage of third down
    conversions - turnover ratio - number of real blonde cheerleaders
    between the 20-40 yard line markers.  Statistically, the best team
    seems to win about 70% of the time - the rest of the time, it's a
    crap shoot.  And there's always one week per season when almost
    every division leading team loses.

[End of excerpt]
-- 
Greg "Mockingbird" Franklin  "People that are really very weird can get into
f67700241@ccit.arizona.edu   sensitive positions and have a tremendous impact
Keep circulating the tapes.      on history." -- Dan Quayle, on Malcolm X

"Father yes son, I want to kill you.  Mother, I want to----WUAAAAAAAAAAARGH!"
	-- Jim Morrison, waxing poetic on family values
"The President scores much better than Bill Clinton."
	-- Dan, comparing Bush's record of marital infidelity to Clinton's
Newsgroups: rec.sport.football.pro