# King Crab

## Introduction

King Crab, also known as Belangkai in the Malay language, is a simple game based on a spinner with four sides. The player simply bets on which symbol will appear after a spin.

## Rules

1. The game uses a spinner with four sides. On the sides are a King Crab, Prawn, Flower, and Fish. Players bets on which one will be on top after a spin.
2. Play begins with the player making one of the bets listed below.
3. The first type of bet is on which symbol will win. With four different symbols, there are four such bets available. Wins can pay either 2.85 or 2.9 to 1. The 2.85 win is sometimes expressed as 3 to 1, less a 5% commission on the win amount.
4. The second type of bet covers two symbols. There are six different ways to pick two out of four symbols, and all six of such bets are available. Wins pay 0.95 to 1, which is sometimes expressed as 1 to 1, less a 5% commission.
5. The third type of bet has one symbol that wins, one that is a push, and two that lose. There 12 ways to choose one winning and another pushing symbol, all of which are available to bet. Wins pay 1.95 to 1, which is sometimes expressed as 2 to 1 less a 5% commission on the win.

Please note that many Internet casinos offer this game and express the odds on a "for one" basis.

Following is an image of the betting layout. This game follows the liberal odds on the one symbol bets and expresses everything on a "for one" basis.

Considering the three different types of bets and the number of ways to bet each one, there are 22 total bets on the table.

## Analysis

### One Winning Symbol -- Stingy Rules

The following table shows the probability and contribution to the return for bets on one winning symbol under the stingy rules that pay 2.85 to 1 on a win. In this case, the King Crab is used as an example of the winning symbol. The lower right cell shows a house edge of 3.75%.

### One Symbol Wins -- Stingy Rules

Event Pays Combinations Probability Return
King Crab 2.85 1 0.25 0.7125
All other -1 3 0.75 -0.7500
Total   4 1 -0.0375

### One Winning Symbol -- Liberal Rules

The following table shows the probability and contribution to the return for bets on one winning symbol under the liberal rules that pay 2.9 to 1 on a win. In this case, the King Crab is used as an example of the winning symbol. The lower right cell shows a house edge of 2.5%.

### One Symbol Wins -- Liberal Rules

Event Pays Combinations Probability Return
King Crab 2.9 1 0.25 0.725
All other -1 3 0.75 -0.750
Total   4 1 -0.025

### Two Winning Symbols

The following table shows the probability and contribution to the return for bets on two winning symbols. In this case, the Flower and Fish are used as an example of the winning symbols. The lower right cell shows a house edge of 2.5%.

### Two Symbols Win

Event Pays Combinations Probability Return
Flower or fish 0.95 2 0.5 0.475
All other -1 2 0.5 -0.500
Total   4 1 -0.025

### One Winning and One Pushing Symbol

The following table shows the probability and contribution to the return for bets on one winning and one pushing symbol. In this case, the Prawn is used as the winning symbol and the King Crab as the pushing one, as just an example. The lower right cell shows a house edge of 2.5%.

### One Symbol Wins and Another Pushes

Event Pays Combinations Probability Return
Prawn 1.9 1 0.25 0.475
King crab 0 1 0.25 0.000
All other -1 2 0.50 -0.500
All other   4 1 -0.025

## Strategy

If playing at a casino that follows the liberal rule of paying 2.9 to 1 on a single symbol, then it doesn't matter what you bet, because everything has a house edge of 2.5%. If playing under the stingy rules, then just don't make bets on a single symbol, where the other three symbols lose. Everything else will have a house edge of 2.5%.