Why? Will Smith be the lucky recipient of a brain transplant?
Some defensemen just think the game better than others. DeKeyser looks like one of those types. So while he might stumble next year like you say, he still clearly has a fundamental understanding of the defensive side of the game. Smith hasn't really shown that at any level--and he doesn't produce like Letang or Karlsson either.
And some defensemen look like rock stars when they play alongside a wall like DeKeyser. Be patient.
He better be the next Scottf****** Niedermayer or Drewf****** Doughty or Niklasf****** Kronwall or whatever idealized comparison the Wings scouting staff/Hockey prospects journalists have touted by that time or else you're gonna get it! Corey Perry style.
He will. Trust me. Babs is high on this guy for a reason.