Fractional Voting and Full Voting
In a DPoS mechanism, voters can vote for multiple witnesses. There are two possible ways to distribute the votes:
- Fractional voting
- Full voting
Fractional Voting
In fractional voting, each voter has a certain number of votes V depending on the amount of his deposit. If a voter wants to vote for three candidates, he can assign a votes to candidate A, b votes to candidate B, and c votes to candidate C. In total a + b + c = V.
Full Voting
In a full voting scheme, each voter has a certain number of votes V depending on the amount of his deposit. If he wants to vote for three candidates, he can assign V votes to candidate A, V votes to candidate B, and V votes to candidate C.
Typically, the number of candidates that each voter can vote for, is limited in the full voting scheme.
Different Outcomes
Both voting schemes can have different outcomes.
Let’s consider the following numerical example:
We have two voters and six candidates. Three candidates are elected into the validator pool. Voter A has 51 % of the total stake (and hence 51 % of all votes). Voter B has 49 % of the stake (and hence 49 % of the votes).
Voter A supports candidates 1, 2, and 3. Voter B supports candidates 4, 5, and 6.
In a full voting scheme the votes would loke as follows:
| Candidate | Percentage of Votes | Member of the Pool? | Supported By |
| 1 | 51% | Yes | A |
| 2 | 51% | Yes | A |
| 3 | 51% | Yes | A |
| 4 | 49% | No | B |
| 5 | 49% | No | B |
| 6 | 49% | No | B |
The consequence is that voter A can determine all three candidates that make it into the pool.
In a fractional voting scheme, the outcome is more diverse. The best strategy of voter A is to distribute his votes on two of his favorite candidates and allocate 0 votes to the remaining.
| Candidate | Percentage of Votes | Member of the Pool? | Supported By |
| 1 | 25% | Yes | A |
| 2 | 25% | Yes | A |
| 3 | 0% | No | A |
| 4 | 25% | Yes | B |
| 5 | 24% | No | B |
| 6 | 0% | No | B |
B’s best choice is to vote with 25 % on candidate 4 and 24 % on candidate 5.
In the end, candidates 1, 2, and 4 become validators. A cannot make all of his favorite candidates win in a fractional voting scheme. At least candidate 4, who is supported by B enters the validator pool.
If the validators in the pool are selected with the same likelihood, no matter how many votes they received in the election, the 24% for candidate 5 are lost (he didn’t make it into the pool).
