# Demo Pool Betting

Pool betting is all about odds and betting on a winner, or some combination of winners. This sample program,
written in .NET Core (v2.0), simulates the simple pool betting type of runners, where each runner has some odds
and random events yields a winner. The runners will develop during their lifespan, increasing or decreasing odds,
simulating real world events.

# Mathematics

There is a probability that a runner will end up on a given position in a race. Since each runner has an odds
to win, the probabilities changes accordingly as each runner gets a final position in the race ([Bayes' theorem](https://en.wikipedia.org/wiki/Bayes%27_theorem)).

For instance, assuming four runners, A, B, C and D, with probabilities [A in the first pace] P(A,1) = 1/11
(according to the odds), P(B,1) = 3/11, P(C,1) = 2/11 and P(D,1) = 5/11 (runner D has the best odds in the race),
and iterating through all of the possible outcomes P(A,1), P(A,2), P(A,3), P(A,4), and so on, gives

![probabilities](./Probabilities.png)

To read from the table, simply pick an event, e.g. P(A,1) [A on first place]. Then the row sum specifies that the probability
that either A, B, C or D ends up in the first place is 1, the column sum specifies the probability that runner A
ends up at either first, second, third or forth place is 1.

## Return from betting

Each better puts a wager on a runner. The sum of all wages makes up the total amount to be distributed to
the winners of the race. The betting houses usually takes a cut of the total amount, leaving the remainder to
be distributed to the winners.

# Betting types

The simulator supports simple pool bets where there is a winner in a race.

# Architecture

The demo is divided into two modules, one for handling the events and wages, and one for handling races. There
is a data store with a data model for events and wages. There will be a digitally signed manifest, with payouts,
for each race.

Communication between the modules will be through TCP/IP, and defined XML protocols.

## Data store model

The following data store model supports the simple pool betting type:

![model](./Betting.png)

A pool contains multiple runners. A runner can in turn be selected into several pools. One wage is specific to
one pool, runner and wager. The wager may have several wages in the same and/or multiple pools. The notion of
event is used when the runner win.

## Process flow

The process flow is illustrated with the following BPMN (v2.0):

![flow](./Flow.png)

The flow represents a racing event. Each race is populated with a random number of wages and runners.

# How to run the simulator

Start up the **EventConsole** and the **RaceConsole** (order doesn't matter), then at the **EventConsole**
prompt set the **data connection string** with the command 'sc Data Source=./Store.db' (or any path to where
you want to put the store), generate a number of wagers and runners (use the command 'gw 50' and 'gr 20') (can
be anything up to 1000 of each).

Now you can use the command **race** (or short 'r') to perform a race, with the manifest (reciept) dropped into
the current working directory for the **RaceControl**.

To start **EventConsole** at the command prompt, use the command 'dotnet .\EventConsole.dll', and for the
**RaceControl**, use the command 'dotnet .\RaceControl.dll' at a second command prompt.

The default TCP port used by the consoles is '48801'.