Duval dropped 19 points and added seven assists in Duke's win against Iona. Beyond the arc: Duke is a scary team with Duval making shots Second-seeded Duke opened up its NCAA tournament on a high note, blowing past No. 15 seed Iona 89-67 Thursday in Pittsburgh. The Blue Zone gives three key takeaways and stats from the win and looks forward for the Blue Devils: Three key takeaways: 1. Duke is a scary team with Duval playing well As Trevon Duval goes, so does Duke. He was a force Thursday against the Gaels, helping the offense flow smoothly and score the most points it had since a January win against Wake Forest. Duval finished with 19 points and was a force from deep, nailing 4-of-5 triples to force defenders to play up on him. That opened up the offense for every other Blue Devil—four starters scored 16-plus points. When Duval plays like this, it’s hard to see anyone beating Duke. 2. Defense still a work in progress Although it tightened up eventually, the Blue Devil defense showed it still has some holes. It had generally locked down opponents on the perimeter, but it failed to stop the Gaels in the early going, allowing them to tie the game at 19 in the first half. But it locked in, especially in the second half, when Duke went to a 3-2 zone as opposed to its traditional 2-3. This allowed the Blue Devils to clog up the perimeter—Iona’s lone strength. The Gaels are a potent perimeter team, but Thursday showed Duke is not invincible beyond the arc. Against a team that can make an impact inside, a 3-2 zone likely won’t fly, so it will have to get back to succeeding in the 2-3 if it wants to make a deep run. 3. Rhode Island is going to be tough Don’t look past Rhode Island. Don’t do it. The Rams start four seniors and run four guards on the outside, similar to the attack that Iona ran, but with more talent. Duke might have to lean on the 3-2 zone again, though Rhode Island isn’t nearly as good of a 3-point shooting team as Iona. But where the Rams are really tough is on defense. Rhode Island ranks No. 36 in the country in basketball statistician Ken Pomeroy’s efficiency ratings, and has allowed the fifth-fewest 3-pointers in the country. Duke likely will have to work inside more and won’t be able to count on 13 3-pointers, or four from Duval, to bail its defense out if it struggles at all. Three key stats: Duke wins battle in the paint 46-30 Marvin Bagley III was a force in the paint, scoring 22 points and grabbing seven rebounds to help Duke win the battle in the paint 46-30. 2. Iona shoots 1-of-15 from deep in the second half The Blue Devils’ 3-2 zone locked down the Gaels’ perimeter attack in the second half, allowing them to shoot just 1-of-15 from beyond the arc after shooting 44.4 percent in the first half. 3. Grayson Allen’s nine assists Allen quietly helped facilitate the offense alongside Duval, adding nine assists to go with his 16 points on 4-of-10 shooting from deep. Looking forward: If Duke can maintain this level of play from Duval, it’s hard to see anyone taking it down. Certainly, the Blue Devils will take on much tougher competition than Iona, but if Duval can resurrect the offense, they have a level of balance few teams can match. Duke wasn’t perfect on defense, but it has been lights out overall since switching to the zone, even against high-quality opponents. It’s hard to see the defense falling apart—if anything, a poor showing from Duval is more likely to be the Blue Devils’ undoing.