The damage done

I LOVE MESSING AROUND with all-encompassing uberstatistics as much as any geek, but you often learn more simply by counting stuff nobody has counted before. Take the sack. As NFL passing yards keep rising and offensive schemes keep expanding, sacks are becoming more valuable. The problem is that teams and fans don't know how valuable. Traditional stats can't answer that. But by consulting the play-by-play database kept by ESPN Stats & Info and counting the effects of sacks -- where they happen, when and how they influence games -- we can create a whole new metric (more on that in a minute) and understand the game in a different light. For instance, not all sacks are created equal: Quarterback takedowns vary widely in their effect on games. And in sacks' cumulative impact, the best pass rushers are at least as valuable as garden-variety QBs. NFL GMs, take heed.