1. Michigan State (13-1)
Season so far: The Spartans are No. 1 in the nation after cruising past the likes of Kansas, Providence Louisville and Florida but dropped their Big Ten opener, badly, at unranked Iowa on Tuesday, one day after coach Tom Izzo's father died.
What's next: Izzo's bunch will have to traverse at least another game or two without its best weapon – the ultra-versatile Denzel Valentine, who had a minor knee surgery earlier this month.
2. Purdue (13-1)
Season so far: The Boilermakers have the nation's most efficient defense, per analyst Ken Pomeroy, and arguably its best frontcourt.
What's ahead: Purdue has played the second-toughest nonconference schedule among Big Ten teams. Will the result be fatigue or battle-tested toughness?
3. Iowa (10-3)
Season so far: The Hawkeyes have won every game at home, don't have any embarrassing losses and are about to hit the national rankings after routing the No. 1 Spartans 83-70 on Tuesday.
What's ahead: The senior-laden squad could shoot its way into contention or struggle from a lack of depth over the course of a long, grueling season.
4. Maryland (11-1)
Season so far: Sophomore guard Melo Trimble, the Big Ten preseason Player of the Year, and 6-11 center Diamond Stone, one of the league's most anticipated freshmen, have been the difference-makers.
What's ahead: The Terrapins will have to seize games like the one they lost at North Carolina in early December if they want to be considered national title contenders.