
NHL Aging Curves
I built a set of historical aging curves using goals above replacement (GAR) for every skater from 2011-12 through 2025-26. I converted everything to a per-60 rate to take ice time out of the equation, used a season-over-season delta method to control for survivorship bias, and normalized each season to account for league scoring shifts. Then I bucketed forwards by scoring (Elite/Top-6/Middle/Depth) and defensemen by ice time (Elite/Top Pair/Second Pair/Third Pair) so we're comparing guys to their actual peers instead of lumping a fourth-liner in with McDavid.
A few things jumped out. Offense goes first, while defense is stickier and it's what gives depth players most of their value. Franchise players are elite because they manage to maintain their production for longer, while good but not great players tend to fall off a cliff. Some GMs probably could have made use of this yesterday...
You can read the article here - https://open.substack.com/pub/danbrousseau/p/nhl-aging-curves-peak-plateau-and