Sub-tick
Valve's netcode model in Counter-Strike 2, where every input is timestamped between server ticks instead of being rounded to the nearest one.
On a conventional server, everything that happens during a tick is treated as if it happened at the start of it; at 64 ticks a second that is up to 15.6 ms of pure rounding. Sub-tick has the client report exactly when within the tick the player fired, jumped or started moving, and the server evaluates the action at that moment. Valve shipped it with Counter-Strike 2 in 2023 and argued it made the 64-versus-128 tick rate debate obsolete.
The players weren't entirely convinced. Simulation and client updates still run at 64 Hz, and the first months were full of complaints about shots registering oddly and movement feeling sluggish. The input precision is real; that it alone replaces more ticks was more of a hope.