The stat that (perhaps) defines the Cavs

The lowly Cavs have allowed opponents to shoot 42.4 percent from three-point range this season. (David Liam Kyle/NBAE via Getty Images)

There are a gazillion reasons why the Cavs stink — LeBron James left, they’ve spent most the year without a viable small forward, now Anderson Varejao’s out for the season, and the roster just isn’t very good.

But there’s one stat that encapsulates all of that: The Cavaliers are on pace to be the worst defenders of the three-point shot in league history. As we reach the midway point of the season, Cleveland’s opponents have hit 42.4 percent of their threes — by far the highest mark in the league.

But just how bad is that?

Since the league instituted the three-point line in the 1979-80 season, only one team has allowed opponents to shoot 40 percent or better through an entire season, according to Basketball-Reference: the 2008-09 Kings, who allowed opponents to shoot 40.6 percent from deep. The Cavs are on pace to destroy that mark, though some good ol’ regression to the mean should help Cleveland as the season goes on.

Even more remarkable: Cleveland opponents shoot an average of 21.3 triples per game, the highest mark in the league. In other words: This is not the case of teams being ultra-selective and hitting a small number of high-percentage threes against the Cavs. Opponents are chucking and hitting long shots, and that is one way to go from being one of the best defensive teams in the league to one of the worst in a few short months.

Defending the three-pointer encompasses everything about defense — rotating soundly, closing out, pick-and-roll coverage, defending the post well enough to limit double teams and lots of other stuff. LeBron helped in almost all of those areas, and his quickness, wing span and hustle have helped Miami hold opponents to a league-low 31.6 percent shooting from deep. (In a cruel twist, that number puts Miami on pace to hold opponents to one of the lowest three-point shooting marks of the last decade or so.)

The drop-off isn’t all James, obviously. But folks expected the remaining Cavaliers to struggle on offense and at least hold their own on defense, and the latter just hasn’t happened.