Author diversity decay
Your posts compete with each other. Candidates are sorted by score; your 2nd, 3rd, Nth post each get multiplied down toward a floor.
multiplier = (1 − floor) × decay^N + floor, where N = how many higher-scoring posts of YOURS are already in this viewer's candidate set (N=0 for your best post). Decay and floor values withheld.
What it means for your posts
Volume-posting into the same audience has mechanically diminishing returns — the decay curve is in the code, only its constants are hidden.
See also the 22 scoring signals this adjustment is applied on top of, or run a draft through the checker.