Human nature. Duke basketball coach Jon Scheyer says the Blue Devils “talk about it all time.” In the midst of the nation’s longest winning streak at 12 games in a row, the second-ranked Blue Devils (16-2, 8-0 ACC) are rolling as the premier team in the ACC and the current favorite to win the national championship at the Final Four in San Antonio.Duke, which has won its eight ACC games by an average of 23 points, could join the 1998-99 and 1962-63 squads as the only ones in program history to finish with an undefeated record in league play. The Blue Devils’ toughest opponent the rest of the regular season might very well be human nature, a term former Duke coach Mike Krzyzewski mentioned on numerous occasions during his 42 seasons with the Blue Devils. Scheyer, who is in his third season since succeeding Coach K, shares that sentiment. Behind freshman star Cooper Flagg, the current favorite to win National Player of the Year and the projected No. 1 pick in the 2025 NBA Draft, the Blue Devils have their longest winning streak since the 2014-15 national championship season.“I don’t leave anything unsaid with our guys. We talk about human nature all the time; it’s the hardest thing to beat. I don’t care if you’re a coach, player, staff – whoever you are – if you’re a part of the program, human nature can go a lot of different ways. We address all of that head on,” Scheyer said Monday during the ACC’s weekly coaches teleconference. “We’ve done a ton, way more this year with the mental approach to the game. I think our guys have been really receptive to that. It’s paid off during some of our games when we’ve gotten down. It isn’t just about how you start a game, it’s the middle rounds, it’s the end rounds. I think we’ve had a great approach with that."Duke basketball coach Jon Scheyer says Blue Devils must improve defensively ahead of Wake Forest gameAccording to KenPom.com and BartTorvik.com, the Blue Devils are double-digit favorites in 10 of their final 13 games in the regular season. A neutral-site game against Illinois on Feb. 22 in New York City, along with road trips to Clemson (Feb. 8) and rival North Carolina (March 8) are projected to be the toughest remaining tests for Duke. The Blue Devils don’t play again until a trip to Wake Forest on Saturday (4:30 p.m., ESPN), but the Demon Deacons knocked off Duke in Winston-Salem last season.As the Devils continue to combat complacency and the challenge of dealing with the comforts of success, Scheyer highlighted a "big point of emphasis" leading up to this weekend’s Tobacco Road rivalry matchup.“I haven’t been quite as happy with our defense. I think our defense has not been quite the same level,” Scheyer said. “Part of that is not having Maliq (Brown), it just is. But then part of that is, when you’re playing a lot of games, sometimes there’s slippage with your habits. Some of the things that we’ve been doing early in the season, I don’t feel like we’re at that point right now.” Brown, one of Duke’s best and most versatile defenders, has been sidelined with a knee sprain since going down early in the Blue Devils’ win against Notre Dame on Jan. 11. Scheyer said Brown is “doing great” and “attacking every day,” but he hasn’t returned to the court. Without Brown, Duke’s effective field goal percentage defense has been above 50% in two of the last three games. The Devils only had three such games in the first 15 of the season. It’s nitpicking for a defense that has limited opponents to an average of 59.5 points per game (the sixth-best mark in the nation), but every detail matters for a team hoping to cut down the nets in April. Still, it seems the focus is more on Duke itself, rather than the opponents on its schedule. If the Blue Devils can beat human nature, they just might pull off a perfect record in the ACC. "At the end of the day, our guys have great character. They’re hungry," Scheyer said."We’ve got to continue to check ‘em and test ‘em during practice to make sure … we have to continue to peak. I don’t think we’ve peaked yet. That’s the key. Hopefully, you can continue to win games, but you want to continue to get better. That’s what our focus is this week.” Rodd Baxley covers Duke, North Carolina and N.C. State for The Fayetteville Observer as part of the USA TODAY Network. Follow his ACC coverage on X/Twitter or Bluesky: @RoddBaxley. Got questions regarding those teams? Send them to rbaxley@fayobserver.com.