The Phoenix Suns have been laughably bad in the 4th quarter all season long

The Phoenix Suns have reached a new low in this early season, coughing up a cushy 16-point fourth quarter lead on the road against the Detroit Pistons last night to drop to 8-11 on the season.

The lead was lost in record fashion, as the Suns surrendered an 18-0 run in just over 5 minutes of game time after taking a 104-89 lead with about 7 minutes left. The Pistons scored on 8 of 9 possessions in that run, and on 14 of their last 17 chances in regulation overall. The Pistons are not an offensive juggernaut, but against the Suns they looked like it.

Mind-boggling.

After a somewhat strong start at 7-5, the Suns have lost 6 of their last 7 games in awful fashion. Most were close. All were lost in part by playing the league's worst 4th quarter defense. And it's not particularly close.

The defensive problems don't just start in the 4th. The Suns are also the league's worst second half defense over these past seven games, and the third worst defense over all four quarters.

Every team goes through bad stretches, of course. Before this ignominious run, the Suns were better on that end of the floor. Not great, mind you. But better. From the beginning of the season to November 20 when the Suns stood at 7-5, they played the league's 22nd ranked 4th-quarter defense.

Yet still worse than any defense the Suns have played in years. In each of the last two years under coach Jeff Hornacek and defensive coordinator Mike Longabardi, the undersized Suns played a middle-of-the-pack 4th quarter defense over 82 games (17th overall), which basically matched their defense for all four quarters.

How have they fallen to being the worst in the league?

This year, the Suns promised BETTER defense with the addition of ringleader Tyson Chandler, the steadiness of P.J. Tucker and the growth of Alex Len, Eric Bledsoe and Brandon Knight.

Yet, the opposite is true. With the league trending smaller, the Suns have been unable (or unwilling) to anchor all 48 minutes with Chandler and Len in the middle to protect the rim while the opponent throws out a mid-sized forward at the 5 position much of the time.

But has that been the main culprit? In prior years, the Suns were the ones wanting to go smaller, often playing Markieff Morris in the middle surrounded by shooters and slashers. So not playing enough of Chandler and Len should not SUCH a problem.

Let's dig deeper.

The Suns as a team give up 113.8 points per 100 possessions in the 4th quarter this year over all 19 games. Since the Suns play at a convenient 100 possession pace this year, that would equate to about 28 points allowed in 25 possessions every 4th quarter.

Which Suns players are the culprits? How did it get this bad?

Unfortunately, all of them have been terribad. Take a look at their 4th quarter numbers across the entire team.

You could point a finger at Brandon Knight, who plays about 8.5 of the 12 minutes each 4th and offers up the most matador style defense on the team, per the chart. He's nearly 7 points worse than the league-worst defense overall.

But then you scroll down the list and see that everyone has been gawd-awful. Tyson Chandler, Markieff Morris, P.J. Tucker, T.J. Warren and Eric Bledsoe have all been dragging the team D down with a defensive rating worse than the overall team D.

Only backups Mirza Teletovic, Devin Booker, Alex Len, Jon Leuer and Ronnie Price have been "passable" and that's only relative to the low standard of the starters, and generally against the other team's backups.

None of them have a positive net rating (offense minus defense) in the 4th quarter. Not one. Every one of them is a loser, from the starters to the backups.

Could it be the scheme?

Maybe. While the Suns have the same coaching staff as the prior two years, schemes are always tweaked to the personnel. Knight, Chandler, Teletovic, Leuer, Booker and Price are all new. Warren is getting more run than ever. That's more than half the rotation right there.

But these same schemers have been pretty good in the past two years. Yes, we all know about the buzzer beaters, but the Suns have overall "won" the 4th in 2013-14 and 2014-15 (+2.5 and +5.2 per 100 4th quarter possessions, respectively), while losing it badly so far this year (-7.2 per 100 4th quarter possessions).

So, maybe a bad scheme this year, but maybe not.

It's also a decline in play from the returning players who've been with these coaches for years.

• Eric Bledsoe's 4th quarter defense has fallen from a passable 106.3 rating (and a plus-7 in net rating) last year to 114.5 this year.
• Markieff Morris's 4th quarter defense was 105.5 a year ago. This year: 117.0
• Alex Len was 104.9 last year. 111.3 this year.
• P.J. Tucker was a stingy 102.5 last year. This year? 116.9.
• T.J. Warren had a 101 rating last year. 115.6 this year.
• Even Brandon Knight was 102.5 in his 11 games last year. This year: 120
• All were a net positive last year in the 4th. None are net-positive this year.

In the word of Charles Barkley: turrible.

Something has to change. Much of it is likely due to learning to play with new players. As you can see, the whole second unit is new and the starting lineup as two new faces as well (Knight and Chandler). A tweaked scheme could be tweaked again.

Yet some of it is simply hustle.

The Suns expected P.J. Tucker to be a lockdown defender. He was their best defender a year ago, especially in the 4th quarter. This year, he's the worst. His backup, Warren, is no great defender either so coach Hornacek has no secondary options.

Eric Bledsoe has never been a statistically great defender in the 4th, mainly because he's tasked with taking on the golden age of NBA point guards on a nightly basis while also having to carry the offensive load. But still, he's been awful this year compared to last year in the 4th on defense.

Markieff Morris haters have more gristle to chew on too. Keef has declined just as much as a Bledsoe and Tucker on that end, and like Tucker he hasn't even provided as opposing offense spark.

Tucker and Morris were net-positive last year in the 4th, while this year they are bottoming out.

If it's the scheme changes that are failing the Suns, the coaching staff has work to do. But most of the blame must be placed on execution by the players.

It's as if the players collectively decided they'd be good on D this year, so they've focused all their attention on executing on offense.

The starting lineup of Knight, Bledsoe, Tucker, Morris and Chandler have to set the tone and improve by leaps and bounds in the closing quarter or this will be a long, long season.