Fun with small sample sizes: 5 opening week trends that can't possibly continue

There may not be a more common refrain during opening week than "small sample size."

While a hot stretch or slump later in the season is a mere blip on an otherwise normalized radar, a hot stretch or slump during opening week is your radar until that normalization occurs.

With that said, here are five early season trends you should enjoy while they last, because they most certainly will not.

Everyone is a PER legend

Player Efficiency Rating has its flaws, especially when it comes to defensive evaluation, but if there's one thing all stat-heads can agree on, it's that posting a 30-plus PER is the mark of a truly historical season.

Entering the 2015-16 campaign, only 18 such seasons had ever been recorded (including Anthony Davis' last year), with Wilt Chamberlain's 1962-63 PER of 31.8 leading the bunch.

Through six days of the new season, however, 11 players (Joffrey Lauvergne!) have 30-plus PERs, including seven stars - Stephen Curry, Blake Griffin, Russell Westbrook, Derrick Favors, Ricky Rubio, Greg Monroe, and Dirk Nowitzki - who are doing so while playing at least 25 minutes per game.

Even more absurd, Curry is boasting a PER of 52.35 through three contests, meaning his rating could literally be halved and still rank in the top seven based on last season's final numbers.

James Harden's Rockets are the worst team ever

A losing streak in the middle of the season is merely a rough week in January. A humiliating losing streak to start the season causes mass panic, particularly for teams with championship aspirations.

Enter James Harden's Houston Rockets, a Western Conference finalist only six months ago.

The Rockets have lost three games by a combined 60 points, including a 20-point home loss to the lowly Denver Nuggets and a 20-point loss in Miami that saw Houston blow a 21-point second-half lead.

They're the first team in NBA history to begin a season with three straight 20-plus-point losses, and Harden, an All-NBA First Team member and likely MVP candidate, has shot 22 percent from the field and nine percent from deep.

You don't need to be told that Harden is a great player, that the Rockets are a good team who have missed Dwight Howard in two of those three games, and that they'll quickly right the ship. But if you're reveling in a contender's early season struggles, check out Monday's game against the Oklahoma City Thunder.

The Rockets could be staring at an 0-4 start - something the 67-win, 2006-07 Dallas Mavericks know all about - before the schedule begins to turn in their favor.

The Bucks can't defend

There wasn't a more stunning turnaround than that of the Bucks under Jason Kidd last season, as Kidd (and defensive assistant Sean Sweeney) utilized Milwaukee's freakish length in an aggressive defensive scheme that overwhelmed opponents.

The 2014-15 Bucks allowed a measly 99.3 points per 100 possessions, good enough for a No. 2 ranking sandwiched between the Golden State Warriors and San Antonio Spurs. The 2015-16 Bucks have allowed a league-worst (and historically porous) 117.1 points per 100 possessions through three games.

With games against the anemic Brooklyn Nets and Philadelphia 76ers on tap in the next few days, and reinforcements on the way, Milwaukee's defense should start looking more like itself sooner rather than later.

The Kings are the fastest

That the Kings would play faster under George Karl was a given, but they can't possibly sustain the pace they've played at during their 1-2 start to the season.

The Kings are using over 108 possessions per 48 minutes through three games, roughly 1.7 additional possessions per game than the next fastest team (Boston Celtics). Given that the highest pace recorded in NBA.com's 19-year archive is 102.72 (2009-10 Warriors), and that Sacramento must account for its bruising, star big man getting up and down the court, this number is sure to plummet in the coming days and weeks.

Jrue Holiday's usage

The most Jrue-dependent team Holiday has played on during his six-year career was the 2012-13 76ers, who saw him use 26.6 percent of the team's possessions when he was on the court during his lone All-Star campaign.

Through a couple of games this season, Holiday used an astronomical 36.2 percent of the New Orleans Pelicans' possessions when on the court, which leads the league, according to NBA.com's data.

Given the presence of an all-world talent in Anthony Davis, the ball-dominant Eric Gordon, and the eventual return of Tyreke Evans, it's safe to say Holiday's opening week usage will seem like a sick joke by December.