When using the stat.fallOneCm objective for Scoreboard, the score does not show the correct amount. It will only increase whether you fall a long distance or a short distance. It seems to track the amount of times a player has fallen rather than the distance. However, it will sometimes increase by 2-3, but not for any obvious reason.

To replicate:
-Enter creative or survival with cheats
-Type "/scoreboard objectives add fall stat.fallOneCm Fall Distance"
-Type "/scoreboard objectives setdisplay sidebar fall"
-If you start in Creative, type "/gamemode 0"
-Jump off a small cliff (don't die though)
-compare the "Fall Distance" score to the fall distance listed in the "General" tab of the statistics menu