How does Reddit's algorithm specifically penalize 'vote brigading', and what quantitative metric is used to detect it?

Reddit's algorithm penalizes vote brigading by heavily discounting the impact of votes originating from suspected brigading sources, effectively reducing the post's visibility and potentially leading to account suspensions for those involved. Vote brigading refers to the coordinated effort of a group to upvote or downvote content, often violating Reddit's content policy regarding vote manipulation. The primary quantitative metric used to detect it is the 'Vote Velocity Anomaly,' measured as the rate of vote changes (upvotes or downvotes) significantly exceeding the statistically normal rate for a given subreddit and content type, combined with an analysis of the voting users' history and connections. This velocity is calculated by analyzing vote patterns and looking for statistically improbable spikes in upvotes or downvotes in a short period. If a post experiences a sudden surge of votes far beyond the typical voting rate for similar content within that subreddit, it triggers suspicion. Furthermore, the algorithm analyzes the voting history of the accounts involved. If a large number of accounts that have historically interacted primarily within a specific community suddenly converge to vote on a post in another subreddit, it suggests coordination. Accounts identified as participating in vote brigading may face warnings, temporary suspensions, or permanent bans. The affected content will have its visibility significantly reduced, regardless of the artificial vote count.