Thursday, September 25, 2008

Week 4: BOA

Now, the increasingly popular Bet Optimization Algorithm (BOA). Things should be more exciting this week since there are 3 underdog picks. That means greater risk and greater rewards (or greater losses). Remember, these are all MONEYLINE bets, they are NOT ATS.

I've noticed that as the number of bets increases, the success of BOA increases, so I'll put up 30 bets this time.

1-TEN, 2-DEN, 3-SF, 4-NYJ, 5-TB, 6-ATL, 7-JAX, 8-CIN, 9-SD, 10-BUF, 11-DAL, 12-PHI, 13-BAL


BET BOA ODDS VEGAS PAYOUT % of BANKROLL
PAYOUT
10 82.00% 1.25 5.73% 7.16
8 78.00% 1.53 5.39% 8.25
1 74.00% 1.61 4.90% 7.90
6 65.00% 3.70 4.71% 17.42
3 65.00% 3.00 4.52% 13.56
8,10 63.96% 1.91 3.82% 7.31
6,10 53.30% 4.63 3.66% 16.94
6,8 50.70% 5.66 3.56% 20.15
1,10 60.68% 2.01 3.49% 7.02
3,10 53.30% 3.75 3.46% 12.98
1,8 57.72% 2.46 3.44% 8.47
3,8 50.70% 4.59 3.39% 15.55
2 67.00% 1.21 3.37% 4.07
13 55.00% 2.90 3.35% 9.71
1,6 48.10% 5.96 3.34% 19.89
1,3 48.10% 4.83 3.17% 15.29
3,6 42.25% 11.10 3.14% 34.86
6,8,10 41.57% 7.08 2.82% 19.98
3,8,10 41.57% 5.74 2.66% 15.27
1,6,10 39.44% 7.45 2.65% 19.76
2,6 43.55% 4.48 2.62% 11.74
1,6,8 37.52% 9.11 2.60% 23.69
1,8,10 47.33% 3.08 2.56% 7.89
8,13 42.90% 4.44 2.55% 11.29
12 57.00% 1.59 2.54% 4.04
10,13 45.10% 3.63 2.54% 9.20
3,6,10 34.65% 13.88 2.54% 35.21
6,13 35.75% 10.73 2.52% 27.07
1,3,10 39.44% 6.04 2.49% 15.05
1,3,8 37.52% 7.39 2.46% 18.21

Week 4: Predictions

Here are the week 4 predictions. I'm not putting out the spread picks because I don't think they're accurate enough. As soon as I see some good results, I'll put them out there. Same with the O/U picks.

Most Confident Pick: BUF over STL, 82%; followed by CIN over CLE, 78%
Upset Watch: SF over NO, 65%; ATL over CAR, 65%; BAL over PIT, 55%

MIN at TEN -3
Winner: TEN, 74%

DEN -9.5 at KC
Winner: DEN, 67%

SF at NO -6
Winner: SF, 65%

ARI at NYJ -1.5
Winner: NYJ, 54%

GB at TB -1
Winner: TB, 52%

ATL at CAR -7
Winner: ATL, 65%

HOU at JAX -7
Winner: JAX, 54%

CLE at CIN -3.5
Winner: CIN, 78%

SD -7.5 at OAK
Winner: SD, 52%

BUF -8 at STL
Winner: BUF, 82%

WAS at DAL -10.5
Winner: DAL, 60%

PHI -3 at CHI
Winner: PHI, 57%

BAL at PIT -5
Winner: BAL, 55%

Tuesday, September 23, 2008

Week 3: BOA Results

Wow. Things almost couldn't have gone any better. I say this because I'm extremely pleased with how BOA performed this week. It spread out the risk while still offering a high level of reward. 7 of the 9 teams were correct. 10 of the 19 bets were correct. If only Vegas' 12.5 point favorite, my 90% favorite had beaten one of the worst teams in the league, I'd be much, much happier. So for week 3, if you started with a bankroll of $100, you would have lost $14.38, or -14.38%. I hate to play the 'what if' game, but I can't help myself this week. What if the 12.5 pt favorite, NE, had decided to beat MIA? $100 would have turned into $157.79. Fine. There's always next week.

Tracking BOA: Week 2, started with $100. Up 64.62% week 2, down 14.38% week 3.
Initial Investment: $100
Current Investment: $140.95
ROI: 40.95%

1-ATL, 2-BUF, 3-CHI, 4-MIN, 5-NE, 6-NYG, 7-TEN, 8-WAS, 9-SF, 10-SEA, 11-DEN, 12-PHI, 13-IND, 14-BAL, 15-DAL, 16-SD

BET BOA ODDS VEGAS PAYOUT % of BANKROLL PAYOUT
5 90.00% 1.11 7.21% 8.01
7 87.00% 1.43 6.94% 9.92
6 84.00% 1.11 6.20% 6.88
14 80.00% 1.77 6.12% 10.83
9 79.00% 1.50 5.79% 8.68
5,7 78.30% 1.59 5.76% 9.14
2 79.00% 1.19 5.46% 6.50
5,14 72.00% 1.96 5.14% 10.10
7,14 69.60% 2.53 5.13% 12.98
6,7 73.08% 1.59 5.00% 7.93
5,6 75.60% 1.23 4.97% 6.12
7,9 68.73% 2.15 4.82% 10.35
5,9 71.10% 1.67 4.79% 7.97
13 71.00% 1.43 4.52% 6.46
5,7,14 62.64% 2.81 4.50% 12.64
11 70.00% 1.40 4.48% 6.28
10 71.00% 1.20 4.39% 5.27
5,6,7 65.77% 1.76 4.39% 7.74
5,7,9 61.86% 2.38 4.38% 10.44

Week 3: Results

We had a great week 3, 13-3 (81.3%) picking the winner. The 3 games lost were: CHI in OT (after a penalty that literally took the victory from the Bears), IND (even the Colts aren't choke-proof), and finally NE (WTF?). Didn't do so well against the spread, so I'm going to stop posting against the spread for now. As the weeks go by, the simulations will be more accurate.

Straight % Wins Games Win %

50-59 3 4 75.0%

60-69 3 3 100.0%

70-79 4 5 80.0%

80-89 2 2 100.0%

90-100 1 2 50.0%

Total 13 16 81.3%


KC at ATL -5.5
Winner: ATL, 64%
Spread: ATL -5.5, 52%

OAK at BUF -9.5
Winner: BUF, 79%
Spread: BUF -9.5, 55%

TB at CHI -3
Winner: CHI, 55%
Spread: EVEN

CAR at MIN -3
Winner: MIN, 63%
Spread: MIN -3, 54%

MIA at NE -12.5
Winner: NE, 90%
Spread: NE -12.5, 66%

CIN at NYG -13.5
Winner: NYG, 84%
Spread: NYG -13.5, 51%

HOU at TEN -5
Winner: TEN, 87%
Spread: TEN -5, 77%

ARI at WAS -3
Winner: WAS, 51%
Spread: ARI +3, 61%

DET at SF -4
Winner: SF, 79%
Spread: SF -4, 65%

STL at SEA -9.5
Winner: SEA, 71%
Spread: STL +9.5, 58%

NO at DEN -5.5
Winner: DEN, 70%
Spread: DEN -5.5, 57%

PIT at PHI -3.5
Winner: PHI, 62%
Spread: EVEN

JAX at IND -5
Winner: IND, 71%
Spread: IND -5, 55%

CLE at BAL -2.5
Winner: BAL, 97%
Spread: BAL -2.5, 96%

DAL -3 at GB
Winner: DAL, 54%
Spread: GB +3, 59%

NYJ at SD -9
Winner: SD, 53%
Spread: NYJ +9, 75%

Friday, September 19, 2008

Week 3: BOA

Originally, I decided to put up a simplified version of BOA's results. Bad idea. I'll need to mention a few things first. I chose to leave out bets against the spread and just include moneyline bets, for now. The fundamental reason BOA works is because of inefficiencies in Vegas' line making. After simulating last season, and after extensive backtesting, NFLSim showed a remarkable tendency to assign accurate probability values for games. BOA exploits this. The only way BOA can be successful is if it assigns the correct probabilites to games, enabling for an optimal allocation of funds to different bets with different payouts. The second important point is that every bet is a different amount, based on the difference in those probabilities. Again, I don't feel that the spread predictions have reached that point yet, though I am comfortable with just striaght picking.

At some point I'd like to write up a rigorous mathematical proof showing why this works, but I'll need to meet up with my statistics professor for that.

Before using this table, consider that the season is just beginning; this is only week 3, so the simulations aren't as accurate as they will be. I can't tell you not to bet, but just keep that in mind.

Since Baltimore's win % against Cleveland is so ridiculously high (97%), I decided to run BOA using a more conservative 80%. At 97%, BAL showed up in pretty much every bet. If BAL loses, lots of bets would lose. Better safe than sorry. If you can't tell by now, I like to err on the side of conservatism.

Once more, this is what each heading means:
~"BOA ODDS" are BOA's calculated probability that the particular bet will win.
~"VEGAS PAYOUT" is the payout for that bet according to Vegas, in decimal form.
~"% OF BANKROLL" is the amount bankroll that should be devoted to that bet.
~"POSSIBLE PAYOUT" is the amount won if the bet is won. (BANKROLL * % OF BANKROLL * VEGAS PAYOUT)

Here is the team key, each number corresponds to a particular bet. 1-ATL means that when you see the number 1, it means bet on ATL to win. If you see 5,7, it means parlay NE and TEN.

1-ATL, 2-BUF, 3-CHI, 4-MIN, 5-NE, 6-NYG, 7-TEN, 8-WAS, 9-SF, 10-SEA, 11-DEN, 12-PHI, 13-IND, 14-BAL, 15-DAL, 16-SD


BET BOA ODDS VEGAS PAYOUT % of BANKROLL PAYOUT
5 90.00% 1.11 7.21% 8.01
7 87.00% 1.43 6.94% 9.92
6 84.00% 1.11 6.20% 6.88
14 80.00% 1.77 6.12% 10.83
9 79.00% 1.50 5.79% 8.68
5,7 78.30% 1.59 5.76% 9.14
2 79.00% 1.19 5.46% 6.50
5,14 72.00% 1.96 5.14% 10.10
7,14 69.60% 2.53 5.13% 12.98
6,7 73.08% 1.59 5.00% 7.93
5,6 75.60% 1.23 4.97% 6.12
7,9 68.73% 2.15 4.82% 10.35
5,9 71.10% 1.67 4.79% 7.97
13 71.00% 1.43 4.52% 6.46
5,7,14 62.64% 2.81 4.50% 12.64
11 70.00% 1.40 4.48% 6.28
10 71.00% 1.20 4.39% 5.27
5,6,7 65.77% 1.76 4.39% 7.74
5,7,9 61.86% 2.38 4.38% 10.44

Alright, let's look at this. That table is based on a bankroll of $100. One of the other reasons BOA works is because it spreads risk over numerous bets in a way such that if one bet fails, other bets can still keep you afloat. If you don't feel like making 19 bets, my advice would be to scale the bets that you do make. If you only want to make the top 5 bets, for example, add the top 5 "% BANKROLLs" together. To find the new percentage to bet, divide that bet's "% BANKROLL" by the sum of the 5 "% BANKROLLs". So... 7.21+6.94+6.2+6.12+5.79 = 32.25. Bet 1 will be 7.21/32.25 = 22.36%. Bet 2 will be 6.94/32.35 = 21.51%, and so on. All 5 percentages should add up to 100%.

As you decrease the number of bets, you increase the amount of risk. For example, if you bet all 19 bets and and all teams win except 5-NE, which has a 90% confidence, you will lose 7.91% of your bankroll. If you decide to only bet the top 5 bets, you'll lose 22.36%. It's about all about your tolerance for risk, which is yours to figure out.

I hope this makes everyone happy. If not, send me some angry emails.

Thursday, September 18, 2008

Week 2 Analysis

I'm not gonna lie, week 2 didn't go too well. Though that's not so surprising considering the nature of simulations - accuracy increases as the amount of data increases. Win = Green, Loss = Red, Push = Blue.

NYG -8.5 at STL
Winner: NYG, 76%
Spread: EVEN

IND -2 at MIN
Winner: MIN, 54%
Spread: MIN +2, 58%

NO -1 at WAS
Winner: NO, 61%
Spread: NO -1, 60%

CHI at CAR -3
Winner: CAR, 51%
Spread: CHI +3, 61%

BUF at JAX -5
Winner: BUF, 64%
Spread: BUF +5, 77%

TEN at CIN -1
Winner: TEN, 79%
Spread: TEN +1, 80%

GB -3.5 at DET
Winner: DET, 59%
Spread: DET +3.5, 64%

OAK at KC -3.5
Winner: KC, 81%
Spread: KC -3.5, 72%

SF at SEA -6.5
Winner: SF, 79%
Spread: SF +6.5, 89%

ATL at TB -7
Winner: ATL, 80%
Spread: ATL +7, 92%

SD -1 at DEN
Winner: DEN, 74%
Spread: DEN +1, 75%

BAL at HOU -4.5
Winner: BAL, 70%
Spread: BAL +4.5, 80%

NE at NYJ -1.5
Winner: NYJ, 53%
Spread: EVEN

MIA at ARI -6.5
Winner: ARI, 57%
Spread: MIA +6.5, 61%

PIT -6 at CLE
Winner: PIT, 91%
Spread: PIT -6, 79%

PHI at DAL -7
Winner: PHI, 65%
Spread: PHI +7, 84%

Straight % Wins Games Win %

50-59 2 5 40.0%

60-69 1 3 33.3%

70-79 4 4 100.0%

80-89 0 2 0.0%

90-100 1 1 100.0%

Total 8 15 53.3%





Spread % Wins Games Win %

50-59 0 1 0.0%

60-69 0 3 0.0%

70-79 2 4 50.0%

80-89 2 3 66.7%

90-100 0 1 0.0%

Total 4 12 33.3%

Week 3's Best 5/Worst 5

5 Best QB's by Rating:
1) Matt Cassel, NE
2) J.T. O'Sullivan, SF
3) Jay Cutler, DEN
4) Philip Rivers, SD
5) Aaron Rodgers, GB

5 Worst QB's by Rating:
1) Derek Anderson, CLE
2) Carson Palmer, CIN
3) JaMarcus Russell, OAK
4) Jon Kitna, DET
5) Matt Schaub, HOU
--------------------------------
5 Best Rushing Teams by Yards:
1) Atlanta Falcons
2) Oakland Raiders
3) Baltimore Ravens
4) Tennessee Titans
5) New York Giants

5 Worst Rushing Teams by Yards:
1) Indianapolis Colts
2) Detroit Lions
3) Cleveland Browns
4) Houston Texans
5) Miami Dolphins

Week 3 Predictions

This is the first time NFLSim has predicted all of the favorites to win. Also, something unusual - all home teams are favorites except for DAL at GB. Anyone know when the last time all home teams were favorites? I sure don't.

KC at ATL -5.5
Winner: ATL, 64%
Spread: ATL -5.5, 52%

OAK at BUF -9.5
Winner: BUF, 79%
Spread: BUF -9.5, 55%

TB at CHI -3
Winner: CHI, 55%
Spread: EVEN

CAR at MIN -3
Winner: MIN, 63%
Spread: MIN -3, 54%

MIA at NE -12.5
Winner: NE, 90%
Spread: NE -12.5, 66%

CIN at NYG -13.5
Winner: NYG, 84%
Spread: NYG -13.5, 51%

HOU at TEN -5
Winner: TEN, 87%
Spread: TEN -5, 77%

ARI at WAS -3
Winner: WAS, 51%
Spread: ARI +3, 61%

DET at SF -4
Winner: SF, 79%
Spread: SF -4, 65%

STL at SEA -9.5
Winner: SEA, 71%
Spread: STL +9.5, 58%

NO at DEN -5.5
Winner: DEN, 70%
Spread: DEN -5.5, 57%

PIT at PHI -3.5
Winner: PHI, 62%
Spread: EVEN

JAX at IND -5
Winner: IND, 71%
Spread: IND -5, 55%

CLE at BAL -2.5
Winner: BAL, 97%
Spread: BAL -2.5, 96%

DAL -3 at GB
Winner: DAL, 54%
Spread: GB +3, 59%

NYJ at SD -9
Winner: SD, 53%
Spread: NYJ +9, 75%

Bet Optimization Algorithm

The results for week 2 were none too impressive, but this makes my Bet Optimization Algorithm ("BOA") look much better. Simply put, BOA takes up to 21 individual bets, i.e. NYG win, MIA win, DAL win, MIN +3, etc., the payouts on those bets that Vegas offers, and the confidence NFLSim generates. Using the algorithms, BOA generates the optimal bets as well as what percentage of your bankroll you should wager on each bet. It spits out single bets and parlays of up to 6 teams. I didn't post the BOA's suggestions last week because I didn't want anyone relying on it, but I'll put them up for week 3. Keep in mind, it's still early in the season so things aren't as accurate as they could be, so be careful. Use at your own risk. Anyway, here's what it said to bet on last week. It generated a return on investment of 64% on the bets (all 31 of them). I'd say that's pretty successful.

To make it easier for me, I assign a number to each bet. All bets are on straight up winners on the moneyline, NO SPREAD. If there are numbers separated by a commas, those are parlays. All calculations are based on a total bankroll of $100. Makes calculations easier.

~"BOA ODDS" are BOA's calculated probability that the bet will win.
~"VEGAS PAYOUT" is the payout for that bet according to Vegas, in decimal form.
~"% OF BANKROLL" is the amount bankroll devoted to that bet.
~"POSSIBLE PAYOUT" is the amount won if the bet is won. (BANKROLL * % OF BANKROLL * VEGAS PAYOUT)
~"ACTUAL PAYOUT" is 0.00 if the bet loses or POSSIBLE PAYOUT if it wins.

1-BUF, 2-CHI, 3-DET, 4-MIN, 5-NO, 6-NYG, 7-KC, 8-TEN, 9-ATL, 10-SF, 11-BAL, 12-ARI, 13-NYJ, 14-DEN, 15-PIT, 16-PHI


BET BOA ODDS VEGAS PAYOUT % OF BANKROLL POSSIBLE PAYOUT

ACTUAL PAYOUT
15 91.00% 1.36 4.72% 6.41

6.41
9 80.00% 3.50 4.15% 14.53

0.00
10 79.00% 3.50 4.08% 14.28

14.28
7 81.00% 1.51 3.82% 5.77

0.00
8 79.00% 1.95 3.81% 7.44

7.44
9,15 72.80% 4.76 3.75% 17.85

0.00
10,15 71.89% 4.76 3.69% 17.55

17.55
8,15 71.89% 2.65 3.43% 9.08

9.08
14 74.00% 2.00 3.41% 6.82

6.82
7,15 73.71% 2.05 3.40% 6.99

0.00
9,10 63.20% 12.25 3.36% 41.21

0.00
7,9 64.80% 5.29 3.25% 17.17

0.00
8,9 63.20% 6.83 3.23% 22.05

0.00
7,10 63.99% 5.29 3.20% 16.89

0.00
8,10 62.41% 6.83 3.18% 21.70

21.70
6 76.00% 1.20 3.13% 3.76

3.76
14,15 67.34% 2.72 3.09% 8.41

8.41
16 65.00% 3.50 3.07% 10.76

0.00
9,10,15 57.51% 16.66 3.07% 51.17

0.00
9,14 59.20% 7.00 2.98% 20.88

0.00
7,9,15 58.97% 7.19 2.98% 21.39

0.00
8,9,15 57.51% 9.28 2.96% 27.46

0.00
10,14 58.46% 7.00 2.94% 20.55

20.55
7,10,15 58.23% 7.19 2.93% 21.06

0.00
8,10,15 56.79% 9.28 2.91% 27.05

27.05
7,8 63.99% 2.94 2.89% 8.52

0.00
1 64.00% 2.90 2.88% 8.36

8.36
6,9 60.80% 4.20 2.88% 12.08

0.00
7,8,9,10,15 36.80% 49.06 1.98% 97.36

0.00
7,9,10,15 46.58% 25.16 2.48% 62.51

0.00
1,8 50.56% 5.66 2.34% 13.22

13.22

Total Bankroll: $100
Total Winnings: $164.62
Total Profit: $64.62
Return on Investment: 64.62%

So even when the predictions aren't terribly accurate (53.3%), BOA is able to perform well based on the idea that the probabilities generated by NFLSim are equivalent to the probabilities in reality. Hopefully, for everyone, this will continue.

Wednesday, September 17, 2008

Week 3

I'm still here, just very busy. Things will be up for this weekend as well as an analysis of last week.

Saturday, September 13, 2008

Week 2 Simulated Stats

I got a request to post yards/pass, yards/play, and yards/point, so here they are. Again, remember that it's early in the season, so there isn't very much information for NFLSim to use. At this point in the season it may be better to use the stats for comparisons rather than to use them as definite predictions. I apologize for the (lack of) formatting of the data tables, if anyone knows how to insert tables from Excel, I'd appreciate some help. I already tried copy and paste. The tables won't be pretty this week, hopefully I'll figure it out for next week.

TEAM YDS/PASS YDS/PLAY YDS/POINT
ARI 8.57 6.00 12.46
ATL 11.25 7.85 12.05
BAL 6.35 5.68 13.01
BUF 7.58 5.74 13.34
CAR 6.17 5.30 11.48
CHI 7.81 5.86 15.83
CIN 5.70 4.57 14.54
CLE 6.59 5.80 16.13
DAL 8.46 6.24 14.48
DEN 8.74 6.95 11.95
DET 6.91 5.66 9.64
GB 10.36 8.26 16.35
HOU 5.95 5.10 13.10
IND 7.18 5.65 13.70
JAX 5.64 4.27 8.48
KC 9.19 6.66 10.71
MIA 7.04 5.26 12.40
MIN 6.40 6.11 13.20
NE 6.75 5.08 12.01
NO 7.86 5.99 12.84
NYG 8.00 6.01 12.37
NYJ 8.38 6.22 12.86
OAK 7.50 6.24 19.02
PHI 7.53 6.02 12.08
PIT 8.30 5.98 10.17
SD 7.54 5.90 14.65
SF 8.34 5.87 12.10
SEA 6.06 4.90 13.90
STL 6.21 5.29 13.59
TB 7.59 6.47 14.01
TEN 6.35 5.48 10.91
WAS 5.61 6.04 14.27

Friday, September 12, 2008

Week 2 Predictions

I'm going to withhold the total predictions for this week, but I'll put up the winners and spreads. This week's predictions are going to sound ridiculous. I was actually thinking about waiting another week before putting them up, but I went back and looked at the simulation of last season's week 2 to see how they compared. In both weeks 2 there were many picks of huge underdogs, but that week actually turned out to be a very good one. I won't give out that week's exact numbers because I don't want heightened expectations. Remember, use these at your own risk. If you're in a suicide / survivor pool and you see that SF wins 79% when they're a 7 point dog, use some discretion. Bear in mind it's the beginning of the season, so the picks may not be as reliable because of a lack of data. That said, here we go...

If the confidence is 50%, I'll just write EVEN.

NYG -8.5 at STL
Winner: NYG, 76%
Spread: EVEN

IND -2 at MIN
Winner: MIN, 54%
Spread: MIN +2, 58%

NO -1 at WAS
Winner: NO, 61%
Spread: NO -1, 60%

CHI at CAR -3
Winner: CAR, 51%
Spread: CHI +3, 61%

BUF at JAX -5
Winner: BUF, 64%
Spread: BUF +5, 77%

TEN at CIN -1
Winner: TEN, 79%
Spread: TEN +1, 80%

GB -3.5 at DET
Winner: DET, 59%
Spread: DET +3.5, 64%

OAK at KC -3.5
Winner: KC, 81%
Spread: KC -3.5, 72%

SF at SEA -6.5
Winner: SF, 79%
Spread: SF +6.5, 89%

ATL at TB -7
Winner: ATL, 80%
Spread: ATL +7, 92%

SD -1 at DEN
Winner: DEN, 74%
Spread: DEN +1, 75%

BAL at HOU -4.5
Winner: BAL, 70%
Spread: BAL +4.5, 80%

NE at NYJ -1.5
Winner: NYJ, 53%
Spread: EVEN

MIA at ARI -6.5
Winner: ARI, 57%
Spread: MIA +6.5, 61%

PIT -6 at CLE
Winner: PIT, 91%
Spread: PIT -6, 79%

PHI at DAL -7
Winner: PHI, 65%
Spread: PHI +7, 84%

Prediction Primer

Before I start putting up the picks, I'll write a quick little blurb about what I'll be posting and how to interpret all of the info. A game's prediction will look like the following:

AWAY at HOME, TOTAL
Winner: PICK, %
Spread: PICK, %
Total: PICK, %

NYG -8.5 at STL, 41.5
Winner: NYG, 76%
Spread: NYG -8.5, 50%
Total: OVER, 66%

So that means: The Giants are an 8.5 pt favorite playing in St. Louis. The over/under line is 41.5. NYG wins outright in 76% of the simulations (380 of 500 simulations). NYG covers the 8.5 point spread in half the simulations. The total score exceeds 41.5 points in 66% of simulations. Simple enough, yes?

Last season, it turned out that the confidence when picking winners actually matched the real life probability of that team winning. (One of the first blog entries has more info on that.) If I simulated 100 different match-ups over the course of the season and they all had a confidence of 65%, in reality, 65 of those 100 picks would be correct. That's extremely useful for gambling purposes, so hopefully that correlation will continue, though there are no guarantees.

I'll also be posting weekly offensive, defensive, and overall power rankings and ratings based on my simulations.

I combined the Kelly criterion with some of my own calculations to determine the optimal bets based on the payout of the bet and the confidence of the pick. Check out en.wikipedia.org/wiki/Kelly_criterion for more info. I'll post the results of the calculations as betting suggestions.

I got a request to post some stats from the simulation, so I'll put those up as well.

Any questions/comments, feel free to shoot me an email.

Thursday, September 11, 2008

Pick posting day

Normally I'd like to get the picks up by Thursday. Unfortunately, something came up and I won't be able to post them until tomorrow (Friday). Thanks for understanding.



R.I.P Adrian Cane 9/9/08

Saturday, September 6, 2008

Picks Start Week 2

One last reminder... picks start week 2. There aren't going to be any picks tomorrow. There may be an enlightening article in a few days. But no picks until next week, week 2. Keep checking back, though, some other cool stuff might pop up.

Wednesday, September 3, 2008

Predicting total number of wins using Points

If you're going to devise a system to predict games, where do you start? Some people like to look at total yardage as their primary predictor, various trends and indicators, the type of turf and weather, or "Who would win in a fight: a lion or a bear?". I like to break down a sport to figure out what the absolute deciding factor is in a victory. Total yards? Sometimes a team with greater total yards wins, but sometimes not. Number of touchdowns? Three field goals beats one touchdown. The only factor that ALWAYS holds true in a victory is... number of points. The team with the greater number of points ALWAYS wins. So that must mean that a high scoring team usually beats a low scoring team. Here's some interesting data showing the relationship between points scored and number of wins.

First, let me introduce the concept of 'R-squared' or 'R^2'. R^2 is called the coefficient of determination, it's also the square of the coefficient of correlation. The R^2 value measures how closely a trend line fits the data. It has a value between 0 and 1; 1 meaning the trend line and the data fall exactly on the same line, 0 meaning the data and the trend line have absolutely nothing to do with each other. Therefore, R^2 near 1 says that you've got data which can be approximated by the trend line.

Now I'll show you the remarkable correlation between number of wins and points scored. I looked at both point ratio (points for / points against) and average point differential ((points for - points against)/# of games) for all teams from 2002-2007, that's 6 seasons. For every team, at the end of the season, I calculated their number of wins, their point ratio, and their point differential. I averaged together the point ratio and point differential for all like-numbered wins. For example, I grouped and averaged together all pt. ratios for teams that won 11 games, which gave me the average point ratio for teams that won 11 games.

Results

I chose to exclude teams with 1, 15, and 16 wins because in 6 seasons only 1 team fit into each of those categories. Also, I apologize if the graph is a little hard to read, different monitor resolutions might distort it.

Point ratio fits along the line y = 0.0903x + 0.3304 (y = PF/PA, x = # of wins) with an R^2 value of 0.9842.
Average point differential fits y = 1.8311x - 14.664 (y = Avg. Pt. Differential, x = # of wins) with R^2 value of 0.9969.

If we rearrange these equations, we can use them to give a rough prediction of the number of games a team will win come the end of the season. So, the number of games a team will win is based on the formulae:
Ratio:
Wins = (PF/PA)*11.0742 + 3.6589
Differential:
Wins = [(PF-PA)/Games]*0.5461 + 8.008

If you're going to make a bet with your buddy halfway through the season as to whether the Jets will win 3 or 4 games this season, check one of the equations first. (I like the differential equation more, better R^2 value.)

If you want to predict the outcome of games, you can use this to figure out who is supposed to win based on the number of wins they have left in the season. That may be a little abstract, though. Probably a better way to use this information is to work it into your own method. Even better, take away the idea that incorporating points into a system may be the difference between picking games at 47% and 53%.

Jonathan
Black Box Sports

Questions? E-mail me!

Monday, September 1, 2008

Just a Reminder...

Just a reminder, everyone: The predictions begin week 2, that's Sunday, Sept. 14. Since I need numbers to use in the simulation, I can't simulate week 1. I hate the wait but I'd rather hold off a week than B.S. some results and risk getting off to a bad start.

So keep coming back to NFL Black Box, I'll be posting a new article soon. If anyone has a question they'd like answered, send it in. Else, I'll think of something interesting to write about.


Jonathan
Black Box Sports

P.S. Sweet new logo, right?