Allen did NOT fake a slide. What he did do is decide to slow very slightly AFTER the First Down. Then, he saw the reaction of the Steeler defenders to relax. Where upon he took it upon himself to do a small cut and accelerate.
I’m not sure whether he thought about this move in advance. But,he definitely would have dropped and slid if all those Pitt defenders closed on him. They did not. VERY smart.
KC will close on Sunday, if he makes a similar run.