People often claim that the BFB was nerfed in the Gun Mettle update because it lets the Scout move so fast that he outruns his own hitboxes. However, there's never any actual evidence proving this claim.

The BFB increases the user's movement speed up to 520 units/s with a full "Boost" meter. The game's walking speed limit is 520 units/s and this speed supposedly causes the player's hitboxes to lag too far behind their model.

There are countless demonstrations of what is perceived to be "hitbox lag" demonstrated through screenshots and videos. Their method is to display the frame right before the client receives confirmation of an attack from the server (damage numbers, hit sound, kill feed notice, death animation, ragdoll, etc) and then the frame when the confirmation is received.

However, that method assumes that network latency is nonexistent. The client's attack request actually takes some time to reach the server and then more time for the client to receive confirmation of their attack from the server.…