Wednesday, November 5, 2008

Midseason Progressive Results

And now, what everyone's been waiting for. We're about halfway through the season, so I think it's time to post NFLSim's impressive progressive results. I chose to leave out week 2 because It was still too early for me to be making predictions based on 1 week of data. I'm going to post Accuscore's results as well for a comparison. They're the only other play-by-play NFL simulator I know of and they're a well established, well funded, syndicated, sponsored, and mathematically sophisticated operation. David and Goliath? Let's see...

I'm going to give you several different numbers. First, I'll give you the overall numbers, as in the collective 50-100% predictions for winner, spread, and o/u. Then you'll get their numbers broken down. I'll show you weekly trends, % trends, etc.

Overall numbers:
Winner: 65-34 (65.7%)
Spread: 47-45 (51.5%)
O/U: 50-43 (53.8%)
Spread and O/U combined: 97-88 (53.8%)

Accuscore numbers:
Winner: 87-43 (66.9%)
Spread: 51-50 (50.5%)
O/U: 67-50 (57.2%)
Spread and O/U combined: 118-100 (54.1%)

Accuscore has a slight edge when picking the winner, I have a slight edge picking ATS, and Accuscore has a sizeable advantage picking O/U. BUT! Let's look at how Black Box Sports picks compare when confidence is at least 60%. This confidence is really where NFLSim shines. Here is Black Box Sports's record when the confidence is over 60% compared to Accuscore's overall record (can't find any confidence values for picks). Fasten your seat belts.

Black Box Sports +60%:
Winner: 41-19 (68.3%) ... 22-8 (73.3%) when greater than 70%
Spread: 36-21 (63.2%)
O/U: 21-10 (67.7%)
Spread and O/U: 57-31 (64.7%)
Betting 100 units on the spread and over/under, you made +2290, ROI of 26%, halfway through the season.

Once again, Accuscore's numbers:
Accuscore:
Winner: 87-43 (66.9%)
Spread: 51-50 (50.5%)
O/U: 67-50 (57.2%)
Spread and O/U combined: 118-100 (54.1%)

Picking the winner, I'm ahead by 1.4% when at least 60% confidence, 6.4% when at least 70% confidence. Spread, I'm ahead by 12.7%. O/U, up by 10.5%. Combined, I'm up by 10.6%. That's what I'm talking about. Not to mention I offer all the picks for free... Spread the word everyone.

In tabular format:
Winner
Wins Games Win %

50-59 24 39 61.5%

60-69 19 30 63.3%

70-79 17 24 70.8%

80-89 4 4 100.0%

90-100 1 2 50.0%

Total 65 99 65.7%





Spread
Wins Games Win %

50-59 11 35 31.4%

60-69 24 37 64.9%

70-79 11 16 68.8%

80-89 0 3 0.0%

90-100 1 1 100.0%

Total 47 92 51.1%





Over
Wins Games Win %

50-59 29 62 46.8%

60-69 15 22 68.2%

70-79 2 4 50.0%

80-89 2 3 66.7%

90-100 2 2 100.0%

Total 50 93 53.8%

S&O/U





50-59 40 97 41.2%

60-69 39 59 66.1%

70-79 13 20 65.0%

80-89 2 6 33.3%

90-100 3 3 100.0%

Total 97 185 52.4%

Graphically:
Theoretically, as in, if NFLSim was a perfect analog of reality, those dashed lines would be perfectly in line with the thick black line. It would mean that the confidence values are always spot on and the games end exactly the way they should. If the trend (dashed) lines are below the thick line, the confidence values are not as accurate as reality. The more parallel the thick and trend lines are, the more accurate the changes in confidenc values are, i.e., as confidence increases, the accuracy increases at the correct rate. If that makes any sense. This graph shows all the picks.


You'll notice that above, the win % for 90-100 is at 50%. In week 3, the 90.03% favorite NE lost to MIA. 0.03% is just about a difference of 1 game in the entire set of hundreds and hundreds of simulated games. Had NE been an 89.97% favorite, the graph would look like this:


Check out the 'Wins' line. The Wins line overlaps the theoretical line. You can't even see it. That's absolutely absurd, especially after 100 games. The trendline has a slope of .09, compared to the theoretical line's .1. The "Wins" trendline has an R-squared value (a measure of how closely the data points fit the line) of 0.89. Absolutely insane. In general, I try to temper my enthusiasm, but this is unbelievable... This means that when NFLSim says a team will win 63% of the time, that team will win 63% of the time. For those of you math-minded people, the expected number of wins is approximately 64.15. The actual number of wins is 65. That blows my mind.

Here's a team-by-team accuracy breakdown:

Win % Cover Spread % Over %
ARI 83.3% 40.0% 50.0%
ATL 66.7% 50.0% 33.3%
BAL 57.1% 42.9% 71.4%
BUF 66.7% 50.0% 66.7%
CAR 83.3% 40.0% 50.0%
CHI 50.0% 50.0% 66.7%
CIN 71.4% 71.4% 33.3%
CLE 42.9% 42.9% 57.1%
DAL 57.1% 57.1% 57.1%
DEN 50.0% 33.3% 20.0%
DET 100.0% 66.7% 40.0%
GB 100.0% 66.7% 66.7%
HOU 71.4% 57.1% 85.7%
IND 33.3% 50.0% 33.3%
JAX 33.3% 66.7% 60.0%
KC 83.3% 66.7% 83.3%
MIA 33.3% 66.7% 50.0%
MIN 83.3% 66.7% 50.0%
NE 33.3% 20.0% 20.0%
NO 66.7% 33.3% 50.0%
NYG 66.7% 16.7% 20.0%
NYJ 71.4% 57.1% 57.1%
OAK 57.1% 14.3% 57.1%
PHI 66.7% 0.0% 66.7%
PIT 50.0% 66.7% 66.7%
SD 83.3% 50.0% 33.3%
SEA 83.3% 50.0% 33.3%
SF 50.0% 33.3% 40.0%
STL 57.1% 50.0% 28.6%
TB 71.4% 42.9% 57.1%
TEN 100.0% 66.7% 83.3%
WAS 42.9% 28.6% 33.3%

I'll post some more stats if I have a chance.
Enjoy!

I'd love to hear everyone's reactions and questions, so don't be shy, send me some emails.

2 comments:

  1. There are other NFL-Sim projects out there that I have seen over the years. My memory has hard time remembering the websites of most of them but one of the more popular ones I have followed for several years now is http://www.whatifsports.com/beyondtheboxscore/default.asp .

    They currently are 69.5% SU on all games this season, besting both you and Accuscore by 2+ wins. They also are better ATS at 53.7% on all games (I could not find any confidence predictions).

    But anyway, congrats on beating Accuscore so far. Fairly impressive considering they have more resources and subscription fees coming in.

    ReplyDelete
  2. Thanks for letting me know, I'll check them out.

    If anyone else knows of other NFL simulators, email me or post them in a comment. I'm always interested in seeing other methods and their accuracy.

    Thanks again!

    ReplyDelete