How much open air a jump clears, measured edge to edge rather than centre to centre.
Measured against the simulator: a jump carries the player about 1.46 blocks horizontally before
their feet come back to the height they left at, and it barely depends on the run-up - 0 ticks
gives 1.33 and 40 ticks gives 1.46, because horizontal speed tops out almost immediately. What
makes a gap jumpable is therefore not how far apart the two tiles' centres are but how much
nothing is actually between them, since the player can launch from an overhang and land on one.
How much open air a jump clears, measured edge to edge rather than centre to centre.
Measured against the simulator: a jump carries the player about 1.46 blocks horizontally before their feet come back to the height they left at, and it barely depends on the run-up - 0 ticks gives 1.33 and 40 ticks gives 1.46, because horizontal speed tops out almost immediately. What makes a gap jumpable is therefore not how far apart the two tiles' centres are but how much nothing is actually between them, since the player can launch from an overhang and land on one.