In addition to having the best 1-on-1 perimeter defender in the NBA in Avery Bradley, the Celtics also sport the most impactful team defender in the NBA in Kevin Garnett. And if the numbers posted below are anywhere near the truth, Garnett isn't just the most impactful defender in the NBA this year. He's the most impactufl defender in the NBA this year by A LOT. You know, business as usual. But before I go too egg-head, let me take a minute to put this nerd-ism into context. This article will feature adjusted plus minus (APM). Many people, including a lot of people on here, aren't fans of APM because a) it isn't always easy to understand and b) it's still too "new" to have gained full public acceptance as really useful. To address the second point in particular, I would point this out: over the past decade, there have been several analysts to come along and become the new voice for APM such as Dan Rosenbaum, Stephen Ilardi, or Wayne Winston. You know what happens right around the time they really establish their chops using APM? They get hired by an NBA team to do stats for them. Universally. The only way we as fans know that they've been hired is that their websites all of a sudden stop being updated publicly. For the last several years, the two biggest public sources for adjusted plus minus were Basketball Value and Jeremias Engelmann's site (regularized APM, or RAPM). For the 2012-13 season, mysteriously, both sites have stopped being updated publicly.