Editing Single transferable vote (section)

=== Example for an election with parties ===
Elections with parties are conducted in very similar manner to the non-partisan STV election presented above. Parties actually play no role in STV elections – each voter marks preferences for individual candidates and the voter's secondary preferences may be of a different party.

This example shows election of five members in a district. Party A runs five candidates, Party B runs three, and there is one independent in the race. The election is conducted under STV with the Hare quota, which for five seats is 20% (100% divided by five).

==== First round ====
{| class="wikitable"
!Candidate
! colspan="2" |Party
!Votes
(first preferences)
!Quota
!Elected?
!If elected: surplus votes
|-
|Candidate A1
| style="background:#D10000" |
|Party A
|1%
| rowspan="9" |20%
|
|
|-
|Candidate A2
| style="background:#D10000" |
|Party A
|9%
|
|
|-
|'''Candidate A3'''
| style="background:#D10000" |
|Party A
|'''25%'''
|'''Yes'''
|5%
|-
|Candidate A4
| style="background:#D10000" |
|Party A
|8%
|
|
|-
|Candidate A5
| style="background:#D10000" |
|Party A
|5%
|
|
|-
|Candidate I
|
|Independent
|7%
|
|
|-
|Candidate B1
| style="background:#0008A5" |
|Party B
|11%
|
|
|-
|Candidate B2
| style="background:#0008A5" |
|Party B
|18%
|
|
|-
|Candidate B3
| style="background:#0008A5" |
|Party B
|16%
|
|
|-
| colspan="3" |''TOTAL''
|''100%''
|
|
|
|}
In the first round, the vote tally of the most popular candidate of Party A, Candidate A3, is more than quota, so they win a seat.

==== Second, third and fourth rounds ====
Surplus votes are distributed; the voters of Candidate A3 have marked their second preference for another politician of the same party, Candidate A4, so A4 now receives Candidate A3's surplus votes. This transfer of 5 percent of the votes leaves A3 with the quota (20 percent) and A4 with 13 percent.

In the third and fourth rounds, the least popular candidates are eliminated (Candidates A1 and A5) and their votes transferred to their next preferences. Voters of Candidate A5 are not very partisan, preferring the independent candidate over the other candidates of Party A.

{| class="wikitable"
!Candidate
! colspan="2" |Party
!Votes
!Quota
!Elected?
!If elected: surplus votes
|-
|<s>Candidate A1</s>
| style="background:#D10000" |
|Party A
|1% − 1% = 0%
| rowspan="9" |20%
|
|
|-
|Candidate A2
| style="background:#D10000" |
|Party A
|9% + 1% = 10%
|
|
|-
|'''Candidate A3'''
| style="background:#D10000" |
|'''Party A'''
|25% − 5% = 20%
|'''Yes'''
|'''already elected'''
|-
|Candidate A4
| style="background:#D10000" |
|Party A
|8% + 5% = 13%
|
|
|-
|<s>Candidate A5</s>
| style="background:#D10000" |
|Party A
|5% − 5% = 0%
|
|
|-
|Candidate I
|
|Independent
|7% + 5% = 12%
|
|
|-
|Candidate B1
| style="background:#0008A5" |
|Party B
|11%
|
|
|-
|Candidate B2
| style="background:#0008A5" |
|Party B
|18%
|
|
|-
|Candidate B3
| style="background:#0008A5" |
|Party B
|16%
|
|
|-
| colspan="3" |''TOTAL''
|80% (1 already elected)
|
|
|
|}

==== Fifth and sixth rounds ====
In the fifth round, Candidate A2 is eliminated with all their votes going to the candidate A4, the last remaining candidate from Party A, who is elected. The surplus votes of Candidate A4 are transferred. All the voters who helped elect Candidate A4 prefer the independent candidate to the candidates of the other party so their 3% surplus votes will go to Candidate I in the sixth round.
{| class="wikitable"
!Candidate
! colspan="2" |Party
!Votes
!Quota
!Elected?
!If elected: surplus votes
|-
|<s>Candidate A1</s>
| style="background:#D10000" |
|Party A
|
| rowspan="9" |20%
|
|
|-
|<s>Candidate A2</s>
| style="background:#D10000" |
|Party A
|10% − 10% = 0%
|
|
|-
|'''Candidate A3'''
| style="background:#D10000" |
|'''Party A'''
|'''already elected'''
|'''Yes'''
|
|-
|'''Candidate A4'''
| style="background:#D10000" |
|'''Party A'''
|'''13% + 10% = 23%'''
|'''Yes'''
|3%
|-
|<s>Candidate A5</s>
| style="background:#D10000" |
|Party A
|
|
|
|-
|Candidate I
|
|Independent
|12% + 3% = 15%
|
|
|-
|Candidate B1
| style="background:#0008A5" |
|Party B
|11%
|
|
|-
|Candidate B2
| style="background:#0008A5" |
|Party B
|18%
|
|
|-
|Candidate B3
| style="background:#0008A5" |
|Party B
|16%
|
|
|-
| colspan="3" |''TOTAL''
|80% (1 already elected)
|
|
|
|}

There are now only four candidates remaining and three seats remaining open. The least-popular candidate (Candidate B1) is declared defeated. The remaining three are declared elected regardless of whether they reached the quota.

If there is no reason to establish relative popularity of the elected members, the count ends there when the last seats are declared filled. Candidates A3, A4, I, B2 and B3 were elected.

If the ranking of the successful candidates is important, the vote count process continues into a seventh round.

==== Seventh round ====
If the ranking of the candidates is important, the votes belonging to the eliminated Candidate B1 are transferred as per below, assuming voters' alternate preferences are marked that way.
{| class="wikitable"
!Candidate
! colspan="2" |Party
!Votes
!Quota
!Elected?
!If elected: surplus votes
|-
|<s>Candidate A1</s>
| style="background:#D10000" |
|Party A
|
| rowspan="9" |20%
|
|
|-
|<s>Candidate A2</s>
| style="background:#D10000" |
|Party A
|
|
|
|-
|'''Candidate A3'''
| style="background:#D10000" |
|'''Party A'''
|'''already elected'''
|'''Yes'''
|
|-
|'''Candidate A4'''
| style="background:#D10000" |
|'''Party A'''
|'''already elected'''
|'''Yes'''
|
|-
|<s>Candidate A5</s>
| style="background:#D10000" |
|Party A
|
|
|
|-
|'''Candidate I'''
|
|Independent
|15% + 5% = 20%
|'''Yes'''
|
|-
|<s>Candidate B1</s>
| style="background:#0008A5" |
|Party B
|11% − 11% = 0%
|
|
|-
|'''Candidate B2'''
| style="background:#0008A5" |
|Party B
|18% + 6% = 24%
|'''Yes'''
|
|-
|'''Candidate B3'''
| style="background:#0008A5" |
|Party B
|16%
|'''Yes'''
|
|-
| colspan="3" |''TOTAL''
|60% (2 already elected)
|
|
|
|}

Under STV, candidates A3, A4, I, B2 and B3 were elected.

This vote count varies from the reality of many STV systems because there were no "exhausted" non-transferable votes. In most real-life STV elections, some votes that are set to be transferred cannot be and fewer votes are still in play at the end compared to the first round. As well, the Droop quota is usually used in real-life STV elections. With the Droop quota in effect and five seats to be filled, it would have taken 17 percent to be elected with quota, not 20 percent as under the Hare quota. However, if B2's surplus votes under the Droop quota are transferred to any non–Party A candidate, the same five candidates are elected each time, albeit in a slightly different order.

In the first round, 74 percent of votes were cast for candidates who were successful in the end. In this case, as in all STV elections, about 80 percent or more of the votes were used to actually elect someone. Only the 11 percent of votes cast in the end for B1 were not used to elect someone. The members elected in the district represent the sentiments of a large majority of the voters. Due to the diversity of members elected, each voter has someone elected who shares the party label that they voted for in the first place, even if not the individual candidate they preferred, or has seen the election of the independent candidate that they prefer.

==== Compared to other systems ====
This result differs from the one that would have occurred if the voting system used had been non-PR, such as single non-transferable vote (SNTV), first-past-the-post (FPTP) in five districts, first-past-the-post at-large [[general ticket]] voting (as used to elect members of the US electoral college), or a single-winner winner-take-all system in five districts

This result is different from if all voters could only vote for their first preference but still all seats were filled in a single contest, which is called the [[single non-transferable vote]]. Under SNTV, the five candidates most popular when only first preferences are considered were candidates A2, A3, B1, B2 and B3. This means even though Party B's candidates had less support together, they would have received 60% of seats, and Party A only 40%. In this case, Party A overextended themselves by fielding too many candidates, but even if they had [[Strategic nomination|strategically nominated]] only three, they would not necessarily have been successful in gaining three seats instead of two seats, because one or two of their candidates might have taken the lion share of their party votes, leaving not enough votes for the other(s) to be elected. This could be addressed under SNTV if the party voters used coordinated [[strategic voting]].

If voters could vote for five candidates (but not cast ranked votes){{Snd}}) as under the [[plurality block voting]] system, a type of [[multiple non-transferable vote]]{{Snd}}, Party A could have won all seats, leaving Party B and voters of the independent candidate without representation. This is because if all those who voted for A3 marked their votes for all five of the Party A candidates, every Party A candidate would be among the five candidates with the most votes and would be declared elected. That would mean that a voting block of only 25 percent of the electorate would have all the representation.

Under [[majority block voting]], if voters voted along party lines, every Party A candidate would receive a vote from 48 percent of the voters, and some even up to 55% if voters of Candidate I also vote for some Party A candidates with their 4 other votes. At the same time, Party B's candidates could only get up to 52% of the votes with the same tactics. If the voters are partisan enough, the likely outcome is that party A would take all the seats although Party A took less than half the votes (minority representation) and all other votes are wasted.

In single-winner [[First past the post]], the outcome is uncertain. It likely would be that Party A, with 48 percent of the votes, would achieve a clean sweep of all five seats or that Party A might easily take four of the five seats, with Party B taking just one. (The first case would be achieved by Party B votes being cracked by the district boundaries; the second case would be achieved by Party B voters being mostly packed into just one district, leaving Party A with easy victories in the other four districts.) On the other hand, if districts were drawn in a different fashion, Party A and Party B might divide the seats in a three-to-two ratio. Even under certain circumstances, the independent candidate might take a seat if their supporters are sufficiently concentrated in one district.

STV election results are roughly proportional (as much as the number of seats allows) and take into account more than the first preferences of voters. However, it could happen that the independent candidate is eliminated in an early round and so is unable to receive transfers from party voters. If that happens, the supporters of the independent candidate might aid one or another of the main parties. The five seats would be divided among the two main parties, in a more or less fair fashion.

However, under STV (as seen in the example above), the final result may be modulated by cross-party transfers, say from a party A or B candidate to a candidate of the other party or to the independent candidate. When secondary preferences are applied, some voters who gave their first preference to a candidate from a certain party, if that person cannot be elected, might prefer an independent (or even a rival party candidate) before other candidates of their first choice's party. This means that even if it seems that the outcome over-represents or under-represents some faction (based on first preferences), the outcome actually closely adheres to a combination of the first preferences of many voters and secondary preferences of most of the other voters. Under STV, about 80 percent of voters see their vote used to elect someone they prefer (and even more than that portion see someone they prefer elected, even if their vote itself was not used to elect anyone), while under FPTP, often less than half of the votes are used to elect anyone and only the largest group in each district is represented.

{| class="wikitable"
|+
! colspan="2" rowspan="2" |Party
! Popular vote{{efn|name=1st-preference|Based on 1st preference candidates}}
! colspan="2" | STV{{snd}}Hare quota
! colspan="2" | {{abbr|SNTV|Single non-transferable vote}}{{efn|Based on single vote cast for 1st preferences, no tactical voting}}
! colspan="2" | Plurality block voting{{efn|Likely outcome based on first preferences and assuming most voters also cast their second and third votes for candidates of the same party}}
! colspan="2" | Party-list PR{{efn|name=1st-preference}}
|-
!%
!Seats
!%
!Seats
!%
!Seats
!%
!Seats
!%
|-
| style="background:#D10000" |
|Party A
|48%
|2
|40%
|2
|40%
|5
|100%
|3
|60%
|-
| style="background:#0008A5" |
|Party B
|45%
|2
|40%
|3
|60%
|0
|0%
|2
|40%
|-
|
|Independent
|7%
|1
|20%
|0
|0%
|0
|0%
|0
|0%
|}

STV using the Droop quota produces the same results as STV using Hare in this case. A3 and A4 receive quota on first round or soon after. B2, B3 and the independent are elected at the end due to thinning of the field of candidates to one more than the number of remaining open seats, assuming same rules of transfer as above.