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Football Pool Participants Misunderstand Randomness: Pick a few underdogs they overlook

 Confidence pool, neglected teams, Office pool, Office pool strategy, Weekly Payout  Comments Off on Football Pool Participants Misunderstand Randomness: Pick a few underdogs they overlook
Oct 312009
 

Knowing Win Probabilities is necessary to have a shot at winning your office pool, but it’s not sufficient. It’s not sufficient because Win Probabilities are an open secret: your friends in your pool know them, too. And they’re everywhere, and the best ones are free. Even if they weren’t everywhere, you could estimate your own to a very high degree of accuracy by looking at Vegas money lines. You don’t even have to visit betting websites to see Vegas lines; they’re available in USA Today in plenty of time for you to make your picks.

This is why I make my Win Probabilities available for free as a convenience to my visitors. Mine are based on a generic formula derived from Vegas lines. Other estimates of Win Probabilities, Power Indexes, or rankings abound — one of the longest lived and best known is Jeff Sagarin’s Predicted Points model on USA Today. Brian Burke’s WinChance estimates are made available on the New York Times website after a few weeks into the season, and his record is enviable. I wouldn’t discourage anyone from using them; both are very impressive. But over time, I expect sports bettors and books learn which models work the best and their lines gravitate toward the best models anyway.

The fact that your friends know about Win Probabilities, point spreads, or power rankings means that everyone in your pool will pick mostly favorites, most of the time, and if it’s a confidence pool they’ll rank the teams in descending order by Win Probability. Therefore, most of their pick sheets will look remarkably similar. You need to stand apart.

Predicting upsets is a futile exercise in guessing random outcomes. You can either waste your energy trying to predict upsets, or you can focus instead on which upsets, if they occur due to randomness, will help your picks stand apart. So you need to consider the joint distribution of game outcomes and participant picks. By selectively choosing an upset or two, you can let randomness do your work and when those upsets occur, you will stand apart in your weekly pool results.

 Posted by on October 31, 2009 at 11:50 am

Helpful Information Hidden in Plain Sight: Other Participants’ Picks

 neglected teams, Office pool, Office pool strategy, Weekly Payout, Win probability, WPM  Comments Off on Helpful Information Hidden in Plain Sight: Other Participants’ Picks
Oct 312009
 

If you play office pools using some of the largest online pool websites — ESPN, Yahoo, UPICKEM, etc. — you can see the percentages of other users’ picks for every team. If you take a look at them, you’ll notice they’re remarkably similar. But how do you use this information? Here’s how: it is a decent initial approximation for the percentages of picks in your own local pool.

Let’s say 10% of all users on ESPN picked Cleveland, and you play in a pool with 15 participants. Using the ESPN distribution estimate, that means you can expect 1.5 of your participants picks Cleveland.

But it can’t be 1.5. It could be 1 or 2. It could also be 0, 3, 4, or 5, or more if you’re playing in a pool of Cleveland fans. Given the ESPN probability p, where p=10%, the formula for estimating the probability in an N-participant pool that a certain number i picked a team is:

Combin(N,i)*p^i*(1-p)^(Ni)

Enter that formula in Excel, substitute the is and you can see the probabilities that the number of your friends who picked Cleveland are:

0 21%
1 34%
2 27%
3 13%
4 4%
5 1%

If you’re not considering this for every game every week, you’re short-changing your office pool picks.

 Posted by on October 31, 2009 at 11:25 am

NFL Contrarian: Weekly Payout Maximizing Picks for Week 8

 Confidence pool, neglected teams, Office pool strategy, Weekly Payout  Comments Off on NFL Contrarian: Weekly Payout Maximizing Picks for Week 8
Oct 312009
 

For Confidence Pool participants with fewer than 30 participants, Buffalo is likely to be underbet relative to its WinProbability. You’re more likely to win this week’s payout with these picks: (Buffalo fans, your picks are below)

Points Pick WinProb
13 Buffalo 41%
12 San Diego 87%
11 Chicago 82%
10 Indianapolis 80%
9 Arizona 76%
8 New Orleans 74%
7 Dallas 73%
6 Detroit 61%
5 New York J 60%
4 Baltimore 58%
3 Tennessee 58%
2 Green Bay 58%
1 New York G 52%

For Buffalo fans, if your pool is teeming with other Buffalo fans then Buffalo probably won’t be underbet. Use this pick set instead.

Points Pick WinProb
13 Philadelphia 48%
12 San Diego 87%
11 Chicago 82%
10 Indianapolis 80%
9 Arizona 76%
8 New Orleans 74%
7 Dallas 73%
6 Detroit 61%
5 New York J 60%
4 Houston 59%
3 Baltimore 58%
2 Tennessee 58%
1 Green Bay 58%

If your pool is larger than 30 participants, you’ll need two underbet underdogs. Your choices are below:

For non-Buffalo, non-Philly fans:
Points Pick WinProb
13 Buffalo 41%
12 Philadelphia 48%
11 San Diego 87%
10 Chicago 82%
9 Indianapolis 80%
8 Arizona 76%
7 New Orleans 74%
6 Dallas 73%
5 Detroit 61%
4 New York J 60%
3 Baltimore 58%
2 Tennessee 58%
1 Green Bay 58%

For Buffalo fans:
Points Pick WinProb
13 Philadelphia 48%
12 St. Louis 39%
11 San Diego 87%
10 Chicago 82%
9 Indianapolis 80%
8 Arizona 76%
7 New Orleans 74%
6 Dallas 73%
5 New York J 60%
4 Houston 59%
3 Baltimore 58%
2 Tennessee 58%
1 Green Bay 58%

For Philly fans:
Points Pick WinProb
13 Buffalo 41%
12 St. Louis 39%
11 San Diego 87%
10 Chicago 82%
9 Indianapolis 80%
8 Arizona 76%
7 New Orleans 74%
6 Dallas 73%
5 New York J 60%
4 Baltimore 58%
3 Tennessee 58%
2 Green Bay 58%
1 New York G 52%

 Posted by on October 31, 2009 at 10:50 am
Oct 292009
 

Confidence Favorite WinProb Underdog
13 San Diego 87.2% Oakland
12 Chicago 82.4% Cleveland
11 Indianapolis 80.2% San Francisco
10 Arizona 75.7% Carolina
9 New Orleans 73.5% Atlanta
8 Dallas 73.5% Seattle
7 Detroit 61.1% St Louis
6 New York J 59.8% Miami
5 Houston 58.9% Buffalo
4 Baltimore 58.3% Denver
3 Tennessee 58.1% Jacksonville
2 Green Bay 57.9% Minnesota
1 New York G 52.4% Philadelphia

Expected Points 67
Likely range 47 to 86
Probability of zero upsets 0.5%

Upset Probability Distribution: Week 8
#Upsets Probability
0 0.5%
1 3.2%
2 10.1%
3 19%
4 23.8%
5 21%
6 13.4%
7 6.2%
8 2.1%
9 0.5%
10 0.1%
11 0%
12 0%
13 0%

Expected 4.3
Likely range: 2 to 7

 Posted by on October 29, 2009 at 6:45 pm
Oct 292009
 

Confidence Favorite WinProb Underdog
10 Florida 89.3% Georgia
9 Texas 78.0% Oklahoma St
8 Texas Tech 71.0% Kansas
7 Miami Florida 70.5% Wake Forest
6 Wisconsin 69.6% Purdue
5 California 69.1% Arizona St
4 Boston College 65.4% Central Mich
3 Tennessee 65.4% South Carolina
2 Mississippi 60.5% Auburn
1 USC 59.0% Oregon

Expected Points: 41
LikelyRange: 27 to 54
Probability of Zero Upsets: 2.6%

Predicted Upset Distribution
Upsets
0 2%
1 9%
2 21%
3 27%
4 22%
5 13%
6 5%
7 1%
8 0%
9 0%
10 0%

Expected: 3
Likely Range: 1 to 6

 Posted by on October 29, 2009 at 6:31 am

The Football Pool Strategy Paradox

 neglected teams, Office pool strategy, Weekly Payout  Comments Off on The Football Pool Strategy Paradox
Oct 262009
 

Football pools are not contests of football knowledge or predictive ability:  they’re contests of strategy and discipline.

    Strategy paradox:  Never pick upsets for a season prize; always pick upsets for weekly prizes

For a season payout pool you stand a better chance of winning the prize if you pick all the favorites each week, regardless of whether you believe they’ll actually win.  You don’t realize how overconfident you are in your own beliefs, but if you ignore them and follow the discipline you’ll be in the running entering the final week(s) of the season.

For a weekly payout pool you’ll win more often if every week you selectively pick an upset or two, even if you’re certain those underdogs won’t win.  “Selectively” does not refer to using a better upset prediction model, it refers to picking teams your friends are not picking.

    Discipline:  On weeks when it doesn’t win the weekly payout strategy can make you look like you know nothing about football

Let’s say you’re in a 17 person pool with a weekly payout.  An average participant should expect to win one payout in a 17 week season.  By using the weekly strategy, you could win 2 or 3 times in a season, but you might come in dead last a dozen times too. Even though there’s no cost to losing badly versus losing well, not winning several weeks in a row can undermine your confidence in the strategy

 Posted by on October 26, 2009 at 1:30 pm
Oct 252009
 

8 correct picks yielded 50 points, resulting in 348 points YTD, which ranks just under the 98th %ile on ESPN College Pick ‘Em. The only upsets, both nail biters, were worth 4 (Miami lost to Clemson) and 1 (Mich. St. lost to Iowa), respectively. Guess the Hawkeyes are for real.

 Posted by on October 25, 2009 at 6:44 am
Oct 242009
 

If you’re playing in a pool with Weekly Payouts, you have an opportunity to profit by your friends’ tendency to overpick favorites.

Thousands of simulations using this week’s Win Probabilities and likely user pick distributions reveal the following are the picksheets most likely to win you this week’s payout. “Most likekly” doesn’t refer simply to the underdogs most likekly to win, but to the underdogs most likely to win and not have been picked by others in your pool. The number of upsets is conditional on the number of participants in your pool, which is why there are multiple pick sheets below.

Confidence Scoring
60 or fewer participants
WPM Pick WinProb

13 KANSAS CITY 35%
12 NEW ENGLAND 89%
11 INDIANAPOLIS 86%
10 PHILADELPHIA 71%
9 GREEN BAY 71%
8 NEW YORK G 71%
7 CAROLINA 71%
6 NEW ORLEANS 70%
5 NEW YORK J 68%
4 PITTSBURGH 65%
3 DALLAS 63%
2 HOUSTON 60%
1 CINCINNATI 53%
Expected 62.5

Confidence Scoring
61 or more participants
WPM Pick WinProb
13 KANSAS CITY 35%
12 CLEVELAND 29%
11 NEW ENGLAND 89%
10 INDIANAPOLIS 86%
9 PHILADELPHIA 71%
8 NEW YORK G 71%
7 CAROLINA 71%
6 TEN 70%
5 NEW YORK J 68%
4 PITTSBURGH 65%
3 DALLAS 63%
2 SEA 60%
1 MIA 53%
Expected 57.1

If your pool uses Regular scoring (each correct prediction has the same weight as each other), the same picks and numbers of upsets apply, according to the number of participants in your pool.

 Posted by on October 24, 2009 at 7:38 am