Looking at Line Movement

One question that gets asked a lot over at TMLJ and RMMB is whether you should wait to put your plays in until the last second or place them earlier. I've run the numbers for the 2008 NCAA season so far and the results are inconclusive, which makes me kind of pissy, since I spent a solid 3 hours doing this research.

I need to define something before moving forward. Positive line movement means getting more points for your play. For example, if the Penn State line opens at -15 and closes at -13, that is defined as positive line movement. The opposite is true for negative line movement. Also, I am only looking at games that made my original Tuesday Leans posts throughout the year. I have neither the time nor energy to look up every game. On top of that, I think this is a better sample, since the concern is mainly games to be bet on anyway. The results follow.

For all Tuesday Leans if played early:

Positive Line Movement: 34-44-1
Negative Line Movement: 52-45
No Line Movement: 24-18-2
Total: 110-107-3

For all Tuesday Leans if played at closing line:

Positive Line Movement: 39-40
Negative Line Movement: 32-22
No Line Movement: 24-18-2
Total: 113-105-2

For plays that were included in Tuesday Leans if played early:

Positive Line Movement: 18-20-1
Negative Line Movement: 32-22
No Line Movement: 9-11-2
Total: 59-53-3

For plays that were included in Tuesday Leans if played at closing line:

Positive Line Movement: 22-17
Negative Line Movement: 30-24
No Line Movement: 9-11-2
Total: 61-52-2

One obvious conclusion when looking at the record at the bottom of the list (61-52-2) is that I should not play games that are not on my leans list. This record is relevant because I currently make my plays roughly at the closing line. Added on plays happen because I am following somebody or something catches my eye in my Early Saturday hungover state. Plays added on are 7-12-2. Some might classify that as minus-EV. I call it a drinking penalty.

Beyond that, it appears that making the plays right before kickoff is slightly advantageous if you have no information about which direction any single game is going to move. I don't think you need this post to tell what you should do if you know which way a line is going to move.

If you are interested in playing more with the data, send me an email at:
stallone-dot-am19psu-at-gmail-dot-com and I'll send you the Excel file. There are some things I am still interested in, most notably how much you gain or lose in probability by waiting for a line, but I don't have the time to do that kind of analysis. I'll look at the NFL next week. Comments are especially welcome on this post.