Last year I ventured into the domain of (online) gambling. Given that the industry has been around since forever, I expected most problems to be of the technical kind. As it turned out, the struggle with technology was only part of a bigger problem; to move forward we needed to fully grasp the industry and its consumers. Events started out as a way to dismantle a legacy system, but quickly proved to be an effective tool to gain a deeper understanding of our domain. Visualising event streams, we discovered patterns that helped us identify what drives different types of users. Having a better understanding of what customers are looking for, we dove into existing literature to learn which techniques and models casinos use to cater for each type of user. We learned how to program chance while staying true to the Random Number God. Even when variance is brutal, casinos have enough data and tools to steer clear from the pain barrier. All of this entails interesting problems and software, but isn't my code damaging society? Or is gambling just another human trait?

15. type Box =
| Yellow
| Green
| Red
| Blue
| White
| Purple

16. 





1
2
3
4
5
6

17. type RandomNumber =
| Num1
| Num2
| Num3
| Num4
| Num5
| Num6

18. match rnd with
| Num1 -> Yellow
| Num2 -> Green
| Num3 -> Red
| Num4 -> Blue
| Num5 -> White
| Num6 -> Purple

19. 





1
2
3
4
5
6






Lose
Lose
Win!
Lose
Lose
Lose

20. type BoxValue =
| Win of Multiplier
| Loss
and Multiplier = decimal

21. match box with
| Red -> Win 6M
| _ -> Loss

22. 





1
2
3
4
5
6






Lose
Lose
Win!
Lose
Lose
Lose

23. let box = rng() |> toBox
let value = box |> toValue
{ Box = box; Value = value }

25. 





1
2
3
4
5
6






Lose
Lose
Win!
Lose
Lose
Lose

27. 





1
2
3
4
5
6






Lose
Lose
Win!
Lose
Lose
Lose

29. let run times f =
[ 1 .. times ]
|> Seq.map(fun _ -> f())

30. 1/6
1/6
1/6
1/6
1/6
1/6

31. let payout bets wins =
match bets with
| 0M -> 1M
| _ -> wins / bets

32. let houseEdge bets wins =
match wins with
| 0M -> 1M
| _ -> bets / wins

33. House edge
0%
Payout
100%

35. match box with
| Red -> Win 5M
| _ -> Loss

36. House edge
16%
Payout
84%

38. 





1
2
3
4
5
6






Lose
Lose
Win!
Lose
Lose
Lose

39. 





1 2
3
4 5 6






Lose
Lose
Win!
Lose
Lose
Lose

40. match rnd with
| Num1 | Num2 -> Green
| Num3 -> Red
| Num4 | Num5 | Num6 -> Blue

41. 0/6
2/6
1/6
3/6
0/6
0/6

42. House edge
16%
Payout
84%

49. public interface IStatefulAggregate<TState>
{
TState State();
}
public interface IEventRecordingAggregate
{
IEnumerable<object> Events();
}

50. new Scenario<Player, PlayerState>()
.Given(() => Player.Register("1", "jef"))
.When(sut => sut.Lock())
.ThenState(new PlayerState()
{ Id = "1", Locked = true, Nickname = "jef" })
.ThenEvent(new PlayerRegistered("1", "jef"))
.ThenEvent(new PlayerLocked("1"))
.Run();

99. @