5 probably unsustainable NBA stats and trends

The first week of the NBA season always brings its fair share of overreaction, running the gamut from premature optimism to unnecessary panic.

Sometimes it's hard to remember that an upset or bad stretch during the opening week is no different - and no more meaningful - than a random upset or hot week in the middle of January.

Having said that, the extremely small sample sizes of early November provide us with some entertaining and completely unsustainable numbers, so let's dig into those before teams and players start regressing to the same old mean.

Lakers defense

The fact that this Los Angeles Lakers team is awful defensively, and terrible in general, is no surprise, and is certainly sustainable. But just how terrible they've been on the defensive end was one of the main storylines of the NBA's opening week.

The Lakers' defensive issues are so pressing that there's not even enough time for Kobe Bryant's 33.1 field goal attempts per 100 possessions in this post.

So how bad have they been? The Lakers have given up 120.2 points per 100 possessions, which is 8.7 points worse than the 29th-ranked defense of the Utah Jazz and 5.5 points worse than the worst defensive rating ever recorded, according to Basketball Reference.

In fact, the gap between the Lakers' historically incompetent D and Utah's 29th-ranked defense is about the same as the gap between Utah's defense and that of the 13th-ranked Hawks.

The Lakers are the worst team in the West and are going to be bad on both ends all season, but they can't possibly be this bad defensively for much longer. Everyone, except Lakers fans, should enjoy it while they can.

Warriors and Grizzlies defenses

As bad as the Lakers have been defending opposing teams, the Golden State Warriors and Memphis Grizzlies have been that good.

Both teams are holding opponents below 90 points per 100 possessions right now, with the Warriors boasting a defensive rating of 87.5 and the Grizzlies at 89.5. For what it's worth, NBA.com has defensive ratings as far back as the 1996-97 season, and the closest a team has ever come to a defensive rating below 90 was the 2003-04 Spurs, who allowed 91.6 points per 100 possessions.

Neither team can defend this well over 82 games, but their defenses are certainly worth monitoring through the early stages of the season, especially as they jostle for positioning in the meat grinder that is the Western Conference.

Pelicans shooting blanks

The New Orleans Pelicans found out about the Grizzlies' staunch defense the hard way on Monday, as they shot 33.7 percent in a 93-81 loss in Memphis.

But that's been the norm for New Orleans so far this season, even though their first two games came against the underwhelming defenses of Orlando and Dallas.

Through three games, the 1-2 Pelicans have shot 39.1 percent from the field and 25 percent from three-point territory, both atrocious numbers. Their Effective Field Goal Percentage, which is a better measure since it takes into account the added value of threes, is a deplorable 41.8 percent.

Since the introduction of the three-point shot in 1979-80, no team has posted an eFG% below 42.

This level of shooting impotence is likely unsustainable, but spacing will remain an issue for the Pelicans.

James Harden's impact

James Harden looks more focused on the defensive end, and his 13.5 free throw attempts per game and 40 percent three-point shooting see Harden producing a ridiculous 1.29 points per possession, according to Basketball Reference, but it's the on-court/off-court metrics where Harden's early season value jumps off the page.

The Rockets have a net rating (offensive rating minus defensive rating) of +25.7 with Harden on the floor through their 4-0 start and a rating of -17.5 with The Beard on the bench, according to NBA.com.

Harden is more than capable of turning in an MVP-caliber season, but there's no way he can keep up an on-court/off-court net rating of 43.2. That's beyond absurd.

Anthony Davis' PER

The only players with Player Efficiency Ratings higher than Davis' mark of 33.8 right now have either only played one game (Greg Monroe and Brook Lopez) or are already injured (Russell Westbrook).

Turning in a 30-plus PER season is like the holy grail of advanced basketball stats, with the only players ever to do so going by the names of Wilt Chamberlain, Michael Jordan, David Robinson, Shaquille O'Neal, Tracy McGrady, LeBron James and Dwyane Wade.

Even Kevin Durant's historic season last year fell just short.

Having a serious discussion about a player flirting with a 30 PER season in early November seems ridiculous, and the odds are obviously stacked against The Brow, but if anyone other than LeBron James or Kevin Durant is going to do it, it would probably be Davis.

Don't get excited about Davis' PER yet, but at least keep an eye on it.