When I buy boots of mobility, the alacrity upgrade which states +20 flat movespeed does not work. It gives 13. (Going for 469 to 482) Also, when you buy alacrity and resell it back you keep the +13 movement speed for a short duration. (8-10 seconds it seems)
Arby0997 votesnot sure but I think its because you're hitting the soft MS cap of diminishing returns
Borg Drone2 votesOh is that what it is?
Phoenix Kotori 7 votesMovement speed caps When the raw movement speed is greater than 415, there are two soft caps applied: The raw speed between 415 and 490 gets multiplied by 80%. The raw speed over 490 gets multiplied by 50%.
taking from leaguepedia.
Borg Drone4 votesI learned something new today.