Justin Houston had 22 sacks last year for the Chiefs, just one sack shy of breaking the modern NFL record. Houston did it while playing a full slate of games for the Chiefs, and Kansas City faced 591 pass attempts last year (including sacks). That means Houston recorded a sack on 3.7% of Kansas City’s opponent dropbacks.

That’s very good, although it’s just the 11th best rate since 1982. But we have to remember that sack rates have been steadily declining over the past few decades. For example, from 1982 to 2014, the average sack rate was 6.87%, but the 2014 rate was just 6.35%. In other words, we would need to increase the sack rate last year by 8.2% in order to adjust for era. So if we adjust for Houston’s 3.7% average by multiplying that average by 108.2%, his adjusted sack rate jumps to 4.03%. And that’s the second best rate since 1982. [continue reading…]