==== Proposal: A web-site to maintain a friendly betting pool:

On superbowl sunday, friends come over and watch the game together.
It's always a bit more interesting if there are small amounts of money at stake;
an elegant parimutuel system is described below.


=== Raymund's Parimuteul System(*) 

- Before the game, people can buy a ticket for 25¢.  They
  write down the predicted-winner along with a spread > 0.
  (They can write down any number; it can be a duplicate of another ticket.)
  
- At the end of the game, the winning tickets are those that correctly
  predicted the winning team, 
  and whose predicted spread was 
  *less or* equal than the actual spread.
  
  (That is, *non*-winning tickets are those that chose the losing team,
  or had the winning team but a spread
  that was more than the winning team actually achieved.)

- In order to guarantee at least one winning ticket, the house seeds the
  pot by buying two tickets: predicting each of the two teams with a 
  spread of 1.
  (It's encouraged to give these away to the youngest and the oldest
  attendees.)


  The pot is divided evenly among all the winning tickets, weighted
  by their spread.


== Example: Suppose the Ironers beat the Cowfolk by 10 points.
  Then the winning tickets are all that say 
     “Ironers 𝘯”
  where 1 ≤ 𝘯 ≤ 10.
  Suppose there were four such winning tickets — 
     Ironers 1 (two such tickets), Ironers 3, and Ironers 7.
  The total weight is 1+1+3+7=12, so the tickets 
  are worth 1/12, 1/12, 3/12, and 7/12 of the pot respectively.
  
  Tickets such as Ironers 15 and Cowfolk 2 would not be winning tickets.
    
==  Nice Properties of this system:
- Duplicate tickets are no problem.
- During the game, people can 
  buy/sell/trade their existing tickets based on the game's progress.
- It accomodates risk-takers (betting on larger spreads, for bigger shares)
  and risk-averse 
  (a spread of 1 yields winnings just for predicting the winning team).
- A cheap ticket-price encourages people to buy many tickets at different
  spreads.

== Disadvantage:
- payout requires a bunch of calculation, and a bunch of change.
  (Recommend: round payouts to the nearest nickel, or even the
   nearest quarter.)
   
(*) History:
I first came across this system in Houston in 2004 or so, at a superbowl party
hosted by Raymund Eich.  I *think* he indicated that he did not invent the system himself; however I don't know where he got it from.




=== Program requirements:

- The party-host can go to the website and start a new "room".

- As tickets are bought at the party, the host records them 
  on the website; they are stored in a database.
  (A dropdown menu for the two teams, 
  a numeric field for the predicted spread,
  and another dropdown-or-text-entry of usernames.)
  
- Users can go to the site and see 
  the total pot,
  the tickets they (originally) bought,
  and the current worth of their tickets (should the game end immediately).
  This view should be mobile-frendly.

- A user can enter the ticket-info for some other ticket,
  and see what it's currently worth (should the game end immediately).
  (That is, they can enter a ticket that they don't own.
   It'd be nice to actually note if no-such-ticket is actually in the db;
   regardless the worth should be based on the current pot,
   not the current pot plus 1 for this fictional ticket-info.)

- Willing to develop the code under a creative-commons license.


== Further nice features:
  
- If the host marks a room as "public", anybody can view it; 
  so you can view how your friend's party in a different dorm might be
  betting on the same game.
  
- the ability to easily enter multiple tickets for the same user.

- Ability for people to record that they've transferred(sold) ownership
  of a ticket to somebody else.


- It should be easy for others to download and install the web pages,
  assuming they have a web server with php and mysql installed.

- Various other tools: ability for users to enter "what-if" tickets, 
  ability to print blank ticket templates, a built-in db of team logo/icons;
  the ability for people to enter new team-names+icons, ... .
  
- Are there existing free rss feeds that can be scanned to get the
  most recent scores?



=== Notes on the legality of betting:
Unclear; at the least, make sure the house never takes a cut!;
tout the fact that you are betting on skill, not random events.
(E.g. don't raffle the two house tickets randomly; that'd be luck.)

http://onward.justia.com/2011/01/31/super-bowl-football-pools-are-they-legal/
http://www.nbc12.com/story/21752634/is-your-office-pool-illegal