See the video tutorial for a quick introduction to weighted raffles. You can find details in the text below.
Each entry has an equal chance of winning in most drawings. That said, there are several types of raffles which use different settings and entries can have different chances of winning:
- The more tickets you buy the higher chance to win.
- Purchasers of expensive products have a double chance of winning than purchasers of a basic product line.
- People who did not correctly answer the question are not eligible to win the prize.
— and many other examples.
You can handle entries with different chance of winning in RandomPicker using weights. A weight is a number which increase/decrease the change of winning. The higher the weight the higher probability of being chosen the entry has (1=standard, 2=twice higher probability, 3=triple etc. 0=excluded from the draw). Don’t use decimals, they will be rounded.
If all participants have the same probability to be chosen, leave the weight fields blank — all entries get weight 1 by default. In other cases you need to add values to all participants, even if only a few have higher probability to be chosen.
The maximum weight is 1000. Higher weights will be reduced to 1000, but it can be higher for selected plans.
How it works?
If you use a weight =2 RandomPicker populates the entry twice in the drawing. This causes a double chance to win for the specific entry.
On the other hand, if you use zero value the system excludes the entry from the drawing.
How to assign a weight to the entry?
- You can import weights together with the entry — use the third column of your import file.
- You can change a weight by editing a specific entry which is already in RandomPicker.
The weight function could be misused by organizers who could try to cheat the system. That’s why we apply several anti-cheating measures:
- The usage of weights is always indicated in the public record.
- People can see the weight of each participant in the anonymized list.
- Weight value is displayed for all winners
- Weights have an influence on the project rating score
Multiple entries or weights?
There are two ways how to handle multiple entries in your list. If a person buys for example 10 tickets, you can:
- Put him 10 times to the list;
- Set the weight to «10» for his entry
Both options increase his chance to win 10 times compared to people with a single ticket. The difference is that the person can win several times in option 1. Option 2 assigns a prize to the person only once.
You need to choose which type of drawing your project is at the beginning during the project setup:
Chance of winning:
- «All entries have the same chance of winning»
- «Some entries can have different chance of winning»
If you choose «All entries have the same chance of winning» when creating a new project, you can’t change it later. This is another anti-cheating function requested by laws in many countries.