2007 Results, Analysis, and Betting Applications

Well, since starting back in week 12, I'd say I've gotten some pretty good results. Now before everyone starts yelling at me, I'll preempt it by saying that yes, I know it was only a quarter of the season, and yes, I know that for the spread and o/u it was only a few games. At this point the results may be statistically inconclusive, but it's a start. I worked with what was available- the program was 'completed' in time for week 12. Up until the playoffs, changes were being made to achieve a greater degree of realism. Those changes in no way affected either team exclusively, they affected both teams in exactly the same way.

The results for the playoffs and Super Bowl:

Wins: 4-7 36.4%
Spread: 5-2 71.4%
O/U: 6-1 85.7%

The Law of Any Given Sunday proved too much for me. Though you can't argue with a spread/ o/u combined win percentage of 78.6%


The results for the 2007 regular season, weeks 12 through 16:

Straight-up Wins	% Range	Games	Wins	Win %
	50-59	34	21	61.8%
	60-69	29	19	65.5%
	70-79	14	11	78.6%
	80-89	3	3	100.0%
	90-100	0	0	0.0%
	Total	80	54	67.5%

This is a graph of the above table. It shows the astonishing correlation between the predicted percentages and the real win percentages. The x-axis shows the different % Ranges- like in the tables. The y-axis is the win percentage. So the predicted range 50-59% has a real win percentage of 61.8%. The straight, dark line shows what would happen if all of the teams won exactly as they were supposed to, according to my predicted percentage. Lets say I pick 100 teams to win, and they all fall in 50-59. If my system was perfect, about 55% of those teams would actually win. Since the green line (what actually happened) is so similar to the black line, we're able to conservatively assume that the predicted percentage to win is the same as the real percentage of a straight up win.


Now that we know the probability of a team winning, all of a sudden the moneyline completely opens up. Now we can look at what Vegas is offering and immediately know if it's a statistically favorable or unfavorable bet.

If you have $100 and you make 100 bets at 50% each, and each bets pays out 2:1, then after your 100 bets, you've won 50 of them. Since they pay out 2:1, you've made it back to $100, breaking even. Likewise, if you have $100 and you make 100 bets with a probability of 20%, to break even, each bet must pay 5:1. If each bet pays 4:1, you've won 20 bets, but at 4:1, you only make it back to $80, so you've lost money. At 6:1 you get up to $120. Break-even odds are neutral- in the long run you don't make money, and you don't lose money. We only make bets that are above break-even.

Let's look at the Super Bowl. The Giants were 11.5 dogs. Vegas was offering to pay out 4.25 to 1. The probability that the Giants would win- as calculated by me- was 33%. If you win 33% of your bets, each bet must pay out 3.03:1 (Break-even payout = 1/percentage in decimal form; 1/.33 = 3.03). So, since you need at least 3.03:1 odds to make an intelligent bet, you note that Vegas wants to give you 4.25. 4.25 is bigger than 3.03 so you bet on the Giants to win. And if you had bet on the Giants to win, you'd be one happy camper right now.

Note: If you bet in this manner using a reliable source of percentages, sensible money management, and patience, you'll be successful in the long run...with the moneyline! And it doesn't hurt when you're picking 68% of the games correctly... Of course this also works with the spread and o/u.