Are you sure? Because 70% of zerks nowadays at least have Aspeed amulet and you can't trust your enemy.

Some.of them are friends and there is no reason to lie if u have or not amulet of speed . I think there is a trick in blocking , WHEN TO LAUNCH THE ATTACK , or a trick in defending , when to press the ctrl button . Tricks that i am still a newby and did not find them yet .

There is no trick with that. The only thing that could explain what you're talking about is some latency. You atack so your character launch it on your game client but there is a delay between what you do on your client and when the information is send to the server.