If Duke opens up a big lead against Troy, graduate student Amile Jefferson could finally get some ... Key three: Duke men's basketball vs. Troy The second-seeded Blue Devils' road to Phoenix for the Final Four begins Friday in Greenville, S.C., against No. 15 seed Troy. With Duke coming off a stunning ACC championship run last week, here are three keys for the Blue Devils to avoid what would be an equally shocking upset loss.Defend the 3-point lineMost upsets stem at least in part from hot 3-point shooting, and the Trojans have the weapons from the perimeter to make things interesting Friday night. Junior guard Wesley Person shoots 40.0 percent from long range and exploded for 39 points with 10 made triples in a game against UT Arlington earlier this year.Duke is sixth in the nation in 3-point defense, though, holding opponents to just 29.5 percent shooting from beyond the arc this year. Guards Frank Jackson and Matt Jones have both been excellent perimeter defenders capable of running opposing shooters off the 3-point line, and they will need to contribute more of the same against Person to keep Troy's offense in check.Balanced scoringThe Blue Devils probably will not need all of their perimeter weapons to be clicking to get past the Trojans, but it would help to build on their momentum from last week's ACC tournament, when the team came together consistently for the first time all season. Jayson Tatum, Grayson Allen, Frank Jackson and Luke Kennard each made at least four shots from the field just twice in the regular season, but they replicated the feat in the last two games of the tournament against North Carolina and Notre Dame.If all four are playing well together again Friday, it could be over for Troy quickly and send a message to the rest of the nation's title contenders that Duke belongs in that conversation and last week's breakthrough was no fluke.Expand frontcourt depthGraduate student Amile Jefferson has had an impressive year to cap his college career, but has not received as much help from Duke's younger big men as many expected. Freshman Harry Giles had his best game of the year last Friday against the Tar Heels, but has not been a consistent impact player and rarely plays for more than 15 minutes a game, and classmate Marques Bolden has not scored or played more than four minutes in a game since February. That's not to mention sophomore Chase Jeter, who hasn't played since Jan. 14 due to back surgery and a crowded rotation.If the heavily favored Blue Devils jump out to an early lead and cruise to their first easy win since Jan. 4, Bolden and even Jeter if he is healthy should get their chances on the floor to give Jefferson a breather. A few big plays could give them a confidence boost if they are needed later in the tournament.