Picking apart the projected No. 1 seeds

Entering play Thursday, ESPN's Joe Lunardi projects the Indiana Hoosiers (Midwest), Duke Blue Devils (East), Gonzaga Bulldogs (West) and Kansas Jayhawks (South) to be No. 1 seeds in the NCAA tournament. Since only 41 percent (46 of 112) No. 1 seeds have gone on to reach the Final Four since 1985, we take a look at what could make each of these teams vulnerable come tournament time.

Indiana Hoosiers (24-4, 12-3 Big Ten)

Question mark: defending ball screens

The Hoosiers have excelled offensively, ranking among the best in the nation in both scoring (second) and field goal percentage (fifth). On defense, however, they can be attacked with the ball screen. Indiana is allowing pick-and-roll ball handlers to score 0.85 points per play this season, second-worst among all power six schools. Only Penn State -- which won its first conference game of the season on Wednesday -- has been worse.

Duke Blue Devils (24-3, 11-3 ACC)

Question mark: Ryan Kelly’s impact

Often recognized for his offensive game, Duke has actually missed Ryan Kelly on the defensive end. Since Kelly injured his foot on January 8, the Blue Devils have allowed opponents to score 100.8 points per 100 possessions (187th in D-I) on 46.8 percent shooting (316th in D-I). With Kelly, Duke ranked 25th in defensive efficiency (86.2 points per 100 possessions) and 24th in opponent field goal percentage (37.8). Kelly was particularly effective as an on-ball defender, having held opponents to 21.8 percent shooting on attempts against him (fourth in D-I; min. 100 plays). Will he be as effective if or when he returns to the lineup?

Gonzaga Bulldogs (27-2, 14-0 WCC)

Question mark: strength of schedule

Gonzaga has won 10 straight and 18 of its last 19 games, but have the Zags been tested consistently? According to ESPN’s BPI, Gonzaga has played D-I’s 110th-toughest schedule to date, the worst among all teams currently ranked in the BPI's top 35 teams. Teams that reached the Sweet 16 last season had an average strength of schedule rank of 39.4 and only 13-seed Ohio (138) was ranked outside the top 65.

Kansas Jayhawks (24-4, 12-3 Big 12)

Question mark: transition defense

According to KenPom.com, Kansas is the ninth-tallest team in the country, with an average height of 78.2 inches (6-foot-6). With the help of a tall roster, the Jayhawks rank fifth nationally in blocked shots (184) and have limited opponents to 0.72 points per play in half-court sets this season (ninth in D-I). They have struggled, however, when opponents have gotten out on the break. Kansas has allowed 1.08 points per play in transition, eighth-most in the Big 12 and 279th in D-I.