By BRYAN STRICKLAND

bstrickland@heraldsun.com; 419-6671

DURHAM -- Statistically speaking, Duke has no business entering tonight's Big Ten/ACC Challenge game at Wisconsin undefeated.

Yet the No. 6 Blue Devils are unbeaten because they've taken care of business on the defensive end.

Defense always has been the trademark for Coach Mike Krzyzewski's teams, but this latest team really made its mark in its most recent game, becoming the first Duke team to win a game while shooting less than 30 percent from the floor since 1950.

"We have guys that are embracing getting stops," senior Lance Thomas said. "Defense is how we're going to win big."

The Blue Devils (6-0) certainly have won big in the Big Ten/ACC Challenge, going 10-0 in the event to help the ACC go 10-0 as well (the Big Ten enters tonight's final five games leading x-x).

Tonight's game (9:15 p.m., ESPN) will be among the biggest challenges that Duke has faced over the event's history: Wisconsin (4-1) has won 122 of 132 games at Kohl Center under ninth-year coach Bo Ryan, including a 2-1 mark in the Big Ten/ACC Challenge.

"We know it's going to be a hostile environment, just like last year when we went to Purdue and won," junior Nolan Smith said. "When we go on the road like this, it gets very serious."

The Blue Devils already have shined on a big stage -- albeit a neutral one -- in winning the NIT Season Tip-Off on Friday night in New York.

Defense keyed that title run, with Duke yielding just 38 points Arizona State over the final 35 minutes of their semifinal matchup, then holding Connecticut to 36-percent shooting in the final to overcome 29-percent shooting.

Duke's first six opponents collectively are shooting 36 percent, while Duke's shooting checks in at 45.7 percent. It obviously is early, but that's the biggest gap between Duke and its opponents since the 1998-99 season. A year ago, the gap (1 percent) was the smallest since the 1995-96 season.

Duke has much the same personnel as in 2008-09, so what explains the early spike?

Senior Jon Scheyer thinks it actually is because Duke has similar personnel.

"We're more of an experienced team," he said. "We know what to do."

Scheyer also cited the Blue Devils' increased size as a cause for opponents' shrinking shooting percentage. Smith said it goes beyond mere height, also crediting the impact of both the length and the width of Duke's big bodies and its perimeter players.

"We have big guys inside that are making plays, and our perimeter is so long that we're keeping guys in front of us," Smith said. "I think that frustrates a lot of team's offensively because they can't see a lane to drive.

"Our big guys, they have a lot of fouls to give, so they can be as physical as they want. We'll give hard fouls, and we're going to play physical against teams. No more calling Duke soft."

Wisconsin certainly is no slouch on the defensive end. The Badgers have ranked in the top 10 nationally in seven of the previous eight seasons in scoring defense, a big part of the reason that Ryan ranks second -- sandwiched between UNC coach Roy Williams and Krzyzewski -- in winning percentage for active Division I coaches with at least 500 victories.

In the only previous meeting between the schools, Wisconsin's defense didn't hold up at Cameron Indoor Stadium, with Duke claiming an 82-58 victory in this same event two years ago.

"They have some guys that were in that game two years ago, so it's going to be a tough game going there," Thomas said. " We know those guys didn't forget how we won last game, so we've got to go up there and not let that last game relax us."