SITE NEWS: We are moving all of our site and company news into a single blog for Sports-Reference.com. We'll tag all PFR content, so you can quickly and easily find the content you want.

Also, our existing PFR blog rss feed will be redirected to the new site's feed.

Pro-Football-Reference.com ยป Sports Reference

For more from Chase and Jason, check out their work at Football Perspective and The Big Lead.

More on scoring first and winning

Posted by Doug on October 10, 2008

Yesterday's post and the ensuing discussion inspired me to whip up this little table.

What it shows is the historical win probability of a team that takes a 7-0 lead in the first quarter. It is based on all games since 1978. The twist is that I've grouped the games according to the strength difference between the two teams.

For example, the Eagles and 49ers are playing this weekend and Vegas says that, all things considered, the Eagles are 5 points better and hence have about a 69% chance of winning. Roughly speaking, the table below (the '-5' line in particular) says if the 49ers score a first-quarter TD to take a 7-0 lead, then the 49ers have about a 50/50 shot of winning. If, on the other hand, the Eagles strike first with a first quarter TD, the '+5' line indicates that the Eagles would then have about a 74% chance of winning.

I don't have historical Vegas lines, so I estimated the difference in team quality using the teams' Simple Rating System ratings, with 3 points added to the home team's.

+--------------+--------+---------+--------+
| Quality_diff | number | win_pct | margin |
+--------------+--------+---------+--------+
|          -16 |     20 | 0.14    | -12.5  |
|          -15 |     30 | 0.24    | -10.0  |
|          -14 |     20 | 0.23    | -5.1   |
|          -13 |     26 | 0.24    | -7.0   |
|          -12 |     36 | 0.20    | -7.0   |
|          -11 |     42 | 0.26    | -3.1   |
|          -10 |     54 | 0.18    | -6.4   |
|           -9 |     67 | 0.31    | -5.3   |
|           -8 |     74 | 0.34    | -3.2   |
|           -7 |     88 | 0.40    | -1.9   |
|           -6 |     87 | 0.41    | -0.9   |
|           -5 |    101 | 0.50    | 2.0    |
|           -4 |    131 | 0.50    | 0.1    |
|           -3 |    130 | 0.53    | 3.0    |
|           -2 |    164 | 0.54    | 3.1    |
|           -1 |    134 | 0.53    | 2.9    |
|            0 |    137 | 0.66    | 6.4    |
|            1 |    137 | 0.67    | 6.2    |
|            2 |    166 | 0.63    | 5.3    |
|            3 |    160 | 0.62    | 7.5    |
|            4 |    169 | 0.66    | 7.2    |
|            5 |    149 | 0.74    | 12.3   |
|            6 |    154 | 0.76    | 10.7   |
|            7 |    148 | 0.78    | 13.2   |
|            8 |    136 | 0.77    | 12.5   |
|            9 |    141 | 0.82    | 13.5   |
|           10 |     88 | 0.78    | 13.7   |
|           11 |    106 | 0.82    | 15.2   |
|           12 |     95 | 0.84    | 16.0   |
|           13 |     77 | 0.83    | 17.1   |
|           14 |     72 | 0.86    | 19.5   |
|           15 |     65 | 0.83    | 17.5   |
|           16 |     45 | 0.86    | 18.0   |
|           17 |     40 | 0.90    | 18.6   |
|           18 |     32 | 0.87    | 21.6   |
|           19 |     31 | 0.90    | 22.7   |
|           20 |     27 | 0.90    | 18.9   |
+--------------+--------+---------+--------+

The discussion could go a lot of different ways from here, but I'm short on time, so I'll just invite discussion in the comments.

I'll close with the corresponding chart for a first-quarter field goal to take a 3-0 lead:

+--------------+--------+---------+--------+
| Quality_diff | number | win_pct | margin |
+--------------+--------+---------+--------+
|          -14 |     20 | 0.18    | -10.1  |
|          -13 |     23 | 0.16    | -8.5   |
|          -12 |     35 | 0.22    | -7.6   |
|          -11 |     47 | 0.19    | -8.2   |
|          -10 |     54 | 0.27    | -7.4   |
|           -9 |     57 | 0.22    | -5.7   |
|           -8 |     57 | 0.32    | -4.8   |
|           -7 |     78 | 0.29    | -4.3   |
|           -6 |     77 | 0.37    | -3.3   |
|           -5 |     75 | 0.32    | -2.4   |
|           -4 |     87 | 0.40    | -2.3   |
|           -3 |     85 | 0.43    | -1.3   |
|           -2 |    105 | 0.39    | -1.8   |
|           -1 |    102 | 0.37    | -2.5   |
|            0 |    109 | 0.48    | 2.1    |
|            1 |    125 | 0.54    | 1.7    |
|            2 |    108 | 0.61    | 3.5    |
|            3 |    106 | 0.57    | 3.8    |
|            4 |     99 | 0.65    | 4.9    |
|            5 |     79 | 0.63    | 6.1    |
|            6 |    106 | 0.68    | 7.3    |
|            7 |     84 | 0.72    | 9.2    |
|            8 |    102 | 0.71    | 9.5    |
|            9 |     74 | 0.68    | 7.7    |
|           10 |     71 | 0.72    | 9.1    |
|           11 |     51 | 0.72    | 11.9   |
|           12 |     36 | 0.68    | 7.5    |
|           13 |     40 | 0.79    | 14.8   |
|           14 |     40 | 0.83    | 16.7   |
|           15 |     35 | 0.87    | 16.2   |
|           16 |     20 | 0.86    | 16.3   |
+--------------+--------+---------+--------+

This entry was posted on Friday, October 10th, 2008 at 3:46 am and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.