Voter strength refers to the amount of influence that a BotBr's votes have on battle entry scores. Those with a lower influence do not sway the average voting score as much as a user with a higher influence.
Encourage Voting on All Entries
The fewer entries a BotBr votes on, the less impact their votes have. This impact directly correlates to the number of entries voted on, so if a BotBr votes on all entries submitted in a battle, their votes are weighted at 100%. If some n00b registers only to vote on a friend's single track in the same battle, their vote would have little impact because they only voted on a single entry.
The formula for calculating influence based on the percentage of entries voted on is as follows:
INF * (entry_count / 100) * percent_entries_votable_voted_on