With Duke struggling at times in half court and having their weaknesses on perimeter defense exposed by the Buckeyes, Cook would run the team. That would free up Seth Curry to play the role he had last year—coming off screens to catch and shoot.
Andre Dawkins, who has been inconsistent in the catch & shoot role thus far, would lose his starting spot and come off the bench for Duke.
The change is one of those things that everyone seems to know, but no one has officially said. On his weekly TV show, coach Mike Krzyzewski hinted that change was coming.
Speaking about the tough early schedule, he said, "We didn't know how it was going to turn out, but overall turned out very well. It helped us make some decisions on how we want to move on in future… Now it's time to make the corrections that are needed, based on the competition and experience we've had so far."
What exactly would the change correct and how will the new lineup be different from what we've seen in the first eight games?
Tighter D: Quinn Cook has one of the best plus/minus numbers on the team. That's despite a shooting percentage of .350, meaning the team outscores opponents due to defense and teammates being more involved on offense.
He was on par with Seth Curry through the first seven games, despite playing far fewer minutes. He entered the game to stay with 10:51 remaining against Ohio State, and the two teams played to a 21-21 tie with him running the show.
More aggressive to the post: When Curry brings the ball upcourt, his first move is either a pass around the perimeter or a handoff to a teammate 58.3% of the time. With Cook running the show, that happens on just 47% of possessions.
Unlike Austin Rivers, who dribble drives on 30% of the possessions he runs, Cook isn't charging wildly into the tall trees. He's setting up the offense. His first move is an entry pass to the post 18.75% of the time. Only Tyler Thornton (21.2%) does it more. Curry goes inside just 11.5% of the time. With Mason Plumlee rapidly becoming an offensive force, the Blue Devils will be looking to feed the post more often.
More points for Curry: Cook takes a shot without passing when bringing the ball up about twice as often as Curry does. That's because Curry is shooting .590 on spot up jumpers, where he can catch and shoot, and only .400 on pull up jumpers off the dribble.
On shots when someone would be credited with an assist, Curry is shooting .607, which is 142 points higher than on unassisted shots. In other words, he needs to give the ball up and get it back to be effective, and that neutralizes the inside game.
Unfortunately for Curry, two thirds of his shots this season have been ones he's had to create himself. Having Cook running the offense will allow him to go back to what works for him.
Better shots for teammates: Cook has eight assists on 14 attempts this year. (An attempt is a pass that sets up a teammates shot, regardless of whether he makes it.) That means teammates are shooting .571 when they catch a pass from him.
Tyler Thornton leads the team with a .800 shooting percentage on his assists. Austin Rivers, who drives and dishes inside for layups and dunks, is at .689. Teammates are only converting at a .435 rate on passes from Curry, which means he's not getting them the ball in position to score. That's the second lowest percentage on the team for anyone with at least 10 attempts. Miles Plumlee, who's kicking out for three pointers on most of his attempts, is at .421.
The projected lineup of Rivers, Cook, Mason Plumlee, Curry, and Kelly has only been on the floor together twice this season. They played together for 1:48 of the Davidson game and outscored the Wildcats 9-2. By comparison, in the other 38:12 of the game, every other Duke lineup combination outscored them by only six points. Against Tennessee, they were together for 2:22 and outscored the Vols 5-2.
In their two combined stretches, the lineup shot 4 for 8, with three of the four made shots getting assisted. Duke had three steals and forced six opponent turnovers. Opponents shot just 1 of 7 against the lineup.
There will likely be more changes down the road as players develop and other patterns begin to emerge. But for the time being, the rumored change looks like it will have a significant impact.