Skeletons can move as fast as the player even while drawing their bow back.
Skeletons do not have their aim disrupted by player movement, nor from being struck and knocked back.
Skeletons sometimes fire a bow at the player immediately after coming into line of sight, earlier than possible for a player to respond.
Skeletons can backpedal at full speed while drawing and firing their bow.
These bugs enable skeletons to make combat maneuvers that are impossible for players to match, giving skeletons a strong advantage. This paired with their improved AI for 1.9, and high spawn rate, would make the game unreasonably difficult for newer players. I am a veteran player and am finding skeletons to be giving me a lot of trouble even as I am wearing well-enchanted armor and all other mobs have long since become trivial.
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