After losing to Notre Dame last weekend, Duke dropped out of the AP Top 10 for the first time since November 2007.
After losing to Clemson on Saturday, there's an argument to be made that the Blue Devils no longer belong in the Top 25.
Where did it all go wrong?
In terms of effective field-goal percentage (KenPom subscription required), Clemson has the best defense in the country. Opponents are shooting just 24.6 percent from three-point range against the Tigers, and their block rate ranks eighth in the nation.
As such, we certainly don't want to take away from an incredible defensive effort that held Duke to just nine points over the final 11:51 on Saturday afternoon. Clemson simply outplayed Duke and could be emerging as a sleeper to win 11 or 12 games in conference play.
However, we're left to wonder how the Blue Devils have become a team that is capable of scoring just 59 points in a game after opening the regular season with 59 points by halftime against Davidson.
Earlier this week, the "What's wrong with Jabari Parker?" questions hit something of a breaking point. ESPN's C.L. Brown said Parker merely needs room to grow, arguing that he is a man and not a machine. B/R's C.J. Moore dissected Parker's rut, finding a talented scorer who will inevitably bounce back once he adjusts to the defenses that have adjusted to him.
Long story short: He's just a freshman, and patience is a virtue.
But what do we say when the entire team is struggling?
Being patient isn't going to magically fix a defense that might be worse than that of every ACC team not named Boston College. Patience will solve neither an inability to grab offensive rebounds nor an over-reliance on three players to do all of the scoring.
What then? Is this the end of the line for Duke? Should the Blue Devils pack it in and wait for next year's incredible recruiting class to come to the rescue?
Let's not get carried away. It's only mid-January, and Mike Krzyzewski is still one of the greatest basketball coaches of all time. Getting this team in shape for a Final Four run might be his biggest in-season challenge of the past decade, but here are a few things that could help the process.
Switch to Zone Defense
The Blue Devils may not have statistically led the nation in drawn charges over the last 30 years (good luck finding that data), but they certainly did from an anecdotal standpoint. Ask any self-respecting Duke hater, and they'll tell you that Coach K's team drew a charge on 110 percent of its defensive possessions.
So it stands to reason that no team in the country suffered a greater negative impact on defense due to the offseason change to the block/charge rule.
A low-scoring forward who'd perfected the art of dropping like a sack of bricks at the first sign of contact has been a staple on this team for quite some time. From David McClure to Lance Thomas, Miles Plumlee and Josh Hairston, Duke has always had a big man in the paint with a knack for stepping in front of driving guards at the last second.
But now it no longer has that option. Not only has the rule change almost entirely erased Hairston's usefulness on the roster, but it forces the guards to play better on-ball defense to stay in front of their respective men—an art they haven't even begun to perfect yet.
It isn't remotely reasonable to expect a team to be able to adopt a new defense at this point in the year, but what's the harm in trying? Man-to-man defense clearly isn't working—particularly when Andre Dawkins is in the game and/or Tyler Thornton is out of it—and a zone defense is arguably the best way to make up for the fact that Duke's most frequent lineup (according to KenPom) consists of 6'8" Parker effectively playing center.
Play Marshall Plumlee
It seems unlikely that Plumlee will ever be the reason this team wins, but he could potentially be the reason they stop losing.
As a team, Duke is averaging just under 10 offensive rebounds per game. Entering play on Saturday, the Blue Devils were tied for 261st in the country in that category. Plumlee has grabbed nine offensive rebounds in 70 minutes of action—or 5.1 per 40 minutes. Amile Jefferson has the next-highest rate at 4.8 offensive rebounds per 40 minutes. After Jefferson, Parker is the best at a rate of 2.7.
Not only is Plumlee the team's best bet for offensive rebounds, but he's also its top shot-blocking option. Plumlee is averaging one block for every 14 minutes on the floor. He's certainly no Manute Bol, but he's better than anything else Duke has to offer.
Parker leads the team with 19 blocks, but he's swatting just one shot for every 24.8 minutes on the court. Semi Ojeleye is the only other person on the team averaging better than one block per 32 minutes, and Ojeleye is finding it even harder to get playing time than Plumlee.
Maybe he has "bumbling big guy syndrome" and can't play more than 15 minutes without fouling out—though committing just five personal fouls all season would seem to disprove that hypothesis—but why not take those 15 minutes and get a few more blocked shots and extended possessions?
If nothing else, Plumlee brings a level of tenacity to the court that no one else on the team seems interested in replicating. He might make some mistakes and miss all of his free throws, but you can't put a price tag on a guy who busts his butt for loose balls and celebrates every slam dunk like he just made a game-winning shot from midcourt.
Make Rasheed Sulaimon Shoot More
Despite having to share the scoreboard with Seth Curry, Mason Plumlee, Ryan Kelly and Quinn Cook, Sulaimon averaged nine field-goal attempts per game during the 2012-13 season.
Things seemed to be trending in that direction again early this season. Through two games, Sulaimon had 19 field-goal attempts—second only to Parker.
But then he disappeared.
Over Duke's last 13 games, Sulaimon has averaged just 4.1 field-goal attempts per game. He's still getting a decent number of minutes, but he's not doing anything with them. He is averaging 13.7 points per 40 minutes. By comparison, Jefferson is averaging 13.8, and Parker is averaging 26.5.
Duke absolutely needs Sulaimon to reassert himself as a scoring threat.
His passivity has forced the team to give more minutes to Dawkins (23.6 points per 40 minutes), which results in a considerably worse lineup on the defensive end of the floor. Also, Cook has filled the void caused by Sulaimon's lack of shooting, but Cook is shooting just 35.0 percent on the season yet leads the team in three-point attempts.
The particularly frustrating thing is that Sulaimon is an even better three-point shooter than he was last year. He's making 42.3 percent of his triples as opposed to 37.1 percent in 2012-13, but he's only attempting half as many of them. Case in point: Duke shot 8-of-25 from three-point range on Saturday against Clemson, but not one of those attempts belonged to Sulaimon.
This team isn't good enough to get by with just three scorers. Either Dawkins needs to improve his defense or Sulaimon needs to improve his offense. At least there's evidence from last season to suggest that the latter is possible.
There ain't no rest for the wicked, as Duke hosts red-hot Virginia on Monday night and has road games against Pittsburgh and Syracuse in the next 21 days. If they don't fix a few things in a hurry, the Blue Devils could be headed for six conference losses for just the second time since the 1995-96 season.
But if you had to pick one coach to turn things around and right the ship, wouldn't it be Krzyzewski?
Kerry Miller covers college basketball for Bleacher Report. You can follow him on Twitter @kerrancejames.