This is just one play, and Arik Armstead is a rookie, but what the heck is going on in it? As you can see, Armstead appears to have a pretty good angle to tackle tight end Tyler Kroft. However, instead of tackling him, Armstead seems to turn up field and away from Kroft.
Is this just a mental mistake of some kind? I think Armstead has shown some solid stuff his rookie year, albeit without a full complement of snaps. But this kind of thing is just so bizarre that I wanted to pull it out for a look. I'm mostly curious how people interpret this.