The Horizon League hasn't provided much of a challenge for Butler, which has used its conference slate to build the longest winning streak in program history.
Siena, meanwhile, has been busy dominating its own league.
Each team should face a stiff test Saturday as two of the nation's top mid-major clubs collide in Indianapolis, with the 18th-ranked Bulldogs looking for their 17th consecutive victory in the first meeting between the schools.
Both teams were No. 9 seeds in last year's NCAA tournament, with Butler making its third straight appearance while the Saints won a first-round game for the second straight season.
The success has continued in 2009-10 - especially for the Bulldogs, who haven't lost in nearly two months. Butler (24-4) has already secured the regular-season Horizon League crown and is one victory away from finishing unbeaten in conference play.
Coach Brad Stevens' team broke the school record by extending its winning streak to 16 with a 73-55 win over Illinois-Chicago on Wednesday, also improving to 12-0 at Hinkle Fieldhouse.
"It means we've been focused during the whole streak," sophomore forward Gordon Hayward said. "You know, it's nice to have the numbers, but we don't focus on the past. We're always looking forward."
Matt Howard led Butler with 17 points and sophomore guard Ronald Nored added a career-high 16, but perhaps the most telling numbers were Illinois-Chicago's 31.4 percent field-goal percentage and Butler's season-low six turnovers.
Strong defense has buoyed the Bulldogs throughout their streak. They've held opponents to 39.6 percent shooting and 57.6 points per game since their last defeat, 67-57 at UAB on Dec. 22.
"(The streak) is meaningful, but it's not something that we've talked about," Stevens said. "Maybe we'll sit and enjoy it in April or May, but not now - especially with the team we have coming in here Saturday."
Siena (22-5) is likely the best team the Bulldogs have faced during their run. The Saints have already secured the Metro Atlantic Athletic Conference's regular-season title, and they had won 15 straight before an 87-74 loss at Niagara on Feb. 12.
They bounced back with a 74-57 win at Canisius on Sunday, getting 26 points from senior Alex Franklin along with a 15-point, 17-rebound effort from junior Ryan Rossiter, who has five straight double-doubles.
"It would have been better if we didn't lose in the first place," Siena coach Fran McCaffery said, "but I think ... we have responded well."
Saturday's game is a part of the made-for-TV BracketBusters series on ESPN, and the Saints have played well in those games in recent seasons. They beat Northern Iowa 81-75 on Feb. 21, 2009 after cruising to a 93-70 win at Boise State on Feb. 23, 2008.
They may need another win to bolster their NCAA tournament resume in case they need an at-large bid, but Siena hasn't faced a ranked team this season and hasn't beaten a Top-25 opponent in a true road game since making the jump to Division I in 1976.
"It's easy to see why they've won 15 in a row, why they're ranked," McCaffery said of Butler. "They don't make mistakes, they don't rattle. They get behind, they keep coming."
The Bulldogs had lost BracketBuster games in three straight seasons - including two at home - before winning 75-63 at Davidson on last Feb. 21.