Per the AFC North blog on ESPN…Dick LeBeau explains how he came up with the zone blitz:
“As far as the zone-blitz evolution, necessity is the mother of invention. We had a hole in our defensive concept I think in the National Football League that all pressures were zero coverage. You put everybody at risk. It was a hit-or-miss situation,
as was every snap from that standpoint. But when you blitz max it turns the roll of the dice a little higher. All I was looking for was a safer way to do that. Really there hadn't been that much experimentation going on in that area of keeping pressure on the ball and still playing some area [zone] defense behind it.”
Think about how prevalent the zone blitz and the 3-4 defense have become. What an advantage the Steelers had when they would enter a draft looking for players/positions on defense that other teams didn't need to fill on their roster. The competition for DE/OLB hybrids has increased 10-fold over the past decade.