How does time (recency) influence visibility of content compared with score?

In Reddit's Hot algorithm, time and score are the two inputs, but they interact in a way that gives recency a structural advantage over raw score in most practical scenarios. The algorithm does not simply divide votes by time; it applies a logarithmic weighting to votes and an exponential decay to age. The logarithmic weighting means that the first 10 upvotes on a post carry as much ranking weight as the next 100, which carry as much as the next 1,000. This compresses the effective range of scores: a post with 10,000 upvotes does not rank dramatically higher than a post with 1,000 upvotes when time is held equal, because the logarithm reduces the score differential. The age component introduces exponential decay: every additional hour a post has been live makes it harder to stay near the top of the feed, regardless of how many votes it continues to receive. A post from 24 hours ago needs roughly ten times the score of a fresh post just to maintain the same ranking position. Together, these mechanics mean that upvote velocity — the rate at which votes accumulate in the earliest minutes and hours after submission — is the single most decisive factor in determining whether a post reaches high visibility. A post that receives a burst of 100 upvotes in its first 15 minutes will almost always outperform a post that receives 500 upvotes over 8 hours, even though the latter ends up with a higher absolute score. This dynamic has practical implications: posting when a community's audience is most active (typically weekday mornings in the community's primary time zone) maximizes the chance of rapid early engagement, which is the crucial ingredient for algorithmic lift. The Top sort bypasses time entirely and ranks purely by score, making it the appropriate sort for finding the all-time best content in a community.