The Khalil Mack news hit like an unexpected hurricane. But the winds and waters have calmed and now we can see more clearly. What we can see are the many layers of this stunning trade between the Oakland Raiders and the Bears.



Layer 1



Raiders general manager Reggie McKenzie said half the teams in the league asked about trading for Mack. Why didn’t the other 16? You can call Mack an outside linebacker. You can call him a defensive end. You can call him a pass rusher.



But this is what he really is: a unicorn. Players like Mack rarely exist. And if they do, they do not become available at age 27.



Over the last three years, Mack has averaged 12.1 sacks per season and made the Pro Bowl every year. He’s never missed a game. Mack was the NFL Defensive Player of the Year in 2016, but his best football should be ahead of him.



Great players who are traded or allowed to leave their teams almost always carry some sort of...