Duke’s Grayson Allen battles for a loose ball against Wisconsin’s Traevon Jackson Monday night. (David J. Phillip/Associated Press)

If you thought all the whistles were going in favor of Duke this NCAA tournament, you were right.

One of the most contentious subplots to Duke’s 68-63 victory over Wisconsin, the fifth NCAA championship for the ACC school, was the juxtaposition of fouls. Specifically, how Duke became a darling of the referees during the second half.

After the initial 20 minutes, Duke had been whistled for seven fouls and Wisconsin just two. That isn’t unusual — the Badgers typically defend without sending opponents to the free throw line — but coach Mike Krzyzewski wasn’t going to let the game’s three referees enter the half without a thorough haranguing.

Fast-forward to the second half, and though Wisconsin had a nine-point lead with 13 minutes remaining, the foul disparity had completely flipped. The Badgers had accumulated nine fouls by the nine minute mark, including this highly questionable call on Bronson Koenig:

And this Tyus Jones flop that was rewarded by the ref’s anticipatory whistle:

Coach Bo Ryan was salty about the discrepancy after the game, and while it may not have been the most optically opportune time to criticize the officiating — his team averaged just 12 fouls a game this season but was whistled for 13 fouls in Monday night’s second half alone — he was right. Duke did get all the calls during the NCAA tournament.

According to Ken Pomeroy, Duke’s offensive free throw rate — that is, the ratio of free throws to field goal attempts — was nearly 40 percent this season, which is standard for the Blue Devils.

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The team’s free throw rate for the NCAA tournament fell just under its season average (37 percent), but from the Sweet 16 to the title game, Duke benefited from a tremendous amount of whistles — their combined rate against Utah, Gonzaga, Michigan State and Wisconsin ballooned to 50 percent.

Those extra freebies greatly helped against Wisconsin. The Blue Devils attempted six free throws in a four-minute span immediately after the Badgers opened up a nine-point lead, and those generously awarded attempts kept Duke within striking distance while Justise Winslow and Jahlil Okafor sat on the bench.

On the other side of the ball, Duke’s defensive free throw rate (24 percent) ranked fourth nationally, and without an elite-level shotblocker or a defense that generates steals often, Duke needed to avoid fouling at all costs. They were particularly adept at that during the NCAA tournament, dropping to 19 percent in those six games. If that continued over the course of the season, Duke would have ranked with Arizona (2007) and Connecticut (2009) for lowest rates since Pomeroy began tracking stats in 2002. In other words, they dodged whistles at a historically good rate over the tournament’s short span.

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This isn’t to say the refs were swallowing their whistles when Duke was on defense, nor to suggest refs were singling out the Blue Devils’ opponents for the slightest of infractions. That’s a separate argument. This is simply a presentation of what happened in the tournament, though Coach K may have played a cunning role in exacerbating the foul disparities — and not by barking at the officials.

Much has been made of Duke’s defensive improvements — improving from 0.99 points per possession allowed to 0.90 — but that change helped the Blue Devils at the free throw line on both sides of the court. Krzyzewski’s implementation of a small lineup — Winslow at the 4, Matt Jones at the 3 — meant Duke was not only much quicker in the defensive half court, it created offensive mismatches. Duke used its speed to turn the corner on opponents, getting into the paint, and forcing a defensive reaction.

Grayson Allen is a prime example of how Duke’s lineup shift benefited their free throw rate. Sam Dekker simply couldn’t stay with Allen (neither could the Spartans in the Final Four), and he, along with the other Blue Devils, continually got the edge to draw the foul.

This holds true on defense too. Okafor didn’t magically become a better defender — his best option on pick and rolls is to flat hedge and sink towards the rim — but his teammates could now hide his defensive miscues. Quinn Cook became an aggressive help defender, rushing over and through screens; Winslow has the speed, wingspan, and body control to affect shots without drawing a foul; and even Jones helped contain the halfcourt gaps that bedeviled Duke during the ACC season.

When Amile Jefferson spelled Okafor, the junior proved himself a capable defender who also doesn’t foul much, which further enhanced Duke’s defense and prevented opponents from getting to the stripe.

The result: Duke was whistled for 26 fewer fouls than their foes in the NCAA tournament and shot 50 more free throws. Your eyes did not deceive you. Duke really did get all the foul calls during this postseason. Were they the right calls? That’s a different question, one that will haunt Bo Ryan and Badgers fans all summer long.

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