When performing delta compression you take an older snapshot and use less bits to compress a reasonable delta. Snapshots are time stamped and we can use that to measure the time difference in our delta snapshot as well.
This is useful for example if we have a maximum speed a character can travel at, and we know our snapshot’s age, we know the maximum possible location delta is max speed * delta time, and given our desired precision we then reason how many bits we need for our delta encoding for the positional bits. We may need something special for encoding the Z axis.

Every doubling of the delta time we need to add one bit to achieve our desired precision for the positional bits. A more expensive full snapshot resets this increase over time and can offset

In a game with simple player movement (Counter-Strike) we can use one bit to dictate if X or Y has the largest value, and with Pythagoras, after encoding the largest value, we know the possible range of our smallest value and encode it using less bits.