Ron Hainsey was a plus-30 last season.
That means Ron Hainsey was sixth in the NHL in something, at a time when Ron Hainsey shouldn't be sixth in the NHL in anything. Go back 15 years, and a plus-30 would have been an indisputable measure of a defenseman's prowess. But we've gotten a lot smarter and savvier as hockey fans in that span. We know that the Toronto Maple Leafs gave up more shot attempts and shots on goal than they had themselves when Hainsey was on the ice at 5-on-5. And we know that, relative to his teammates, Hainsey's performance was inferior.
This isn't meant to pick on Ron Hainsey. It's meant to illustrate that advanced stats and analytics have helped expose and supersede the lazy junk numbers we relied on for decades. Well, that and a universal understanding that if a player is skating to the bench when a goal is scored by his teammate, he's a "plus-1" despite having nothing to do with the scoring play. Which is nuts!
For that reason, there's been a tendency to deify analytics.