Previous rules are all designed for hand counting. Meek and Warren STV provide the most accurate proportional representation, but the count must be done with a computer and cannot be done by hand. The basic idea is similar to Fractional Transfer STV. There are two main differences: (1) winning candidates also receive vote transfers from eliminated candidates and surplus votes from other winning candidates, and (2) when a candidate is eliminated it is as if the candidate never entered the election. These changes create a feedback loop of vote transfers which requires a computer to implement.