Rob Ryan's defenses -- now of Saints variety -- are occasionally great. But what else is great is his hair.

Here are four shots of his coif, roughly five years apart, so you can enjoy the evolution of L'essence de Rob.

1. We take you back to 1998, roughly six years after the debut of the always-instructional Achy Breaky Heart.

 

2. Here's a shot of Ryan as linebackers coach of the Patriots, which was between 2000-2003. 

As our Ryan Wilson noted last year, the comparison in the tweet is apt. APT. 

Yep, same dude. The shirt confirms it. (HBO)

3. Here's Rob Ryan, then DC of the Raiders in 2008.

Rob Ryan, circa 2008, coaching with the Raiders.
Tufts baby tufts. (Getty Images)

4. And here we are in present day, where Ryan enjoys a life of Full Lebowski.

All Dude, all the time.
All Dude, all the time in 2014. (Getty Images)

But no Rob Ryan blog post would be complete without a reminder of where we all began back in 1981. We present thee, mythological evidence No. 1.

And No. 2: