The defensive gamble that helped BYU basketball beat Gonzaga, explained

"How did that just happen?"

That's the text message my father sent to me shortly after the conclusion of BYU basketball's thrilling but strange 69-68 road victory over No. 25 Gonzaga on Thursday night.

I didn't really have an answer for him.

It was truly a bizarre game — and an even more bizarre outcome — in almost every way. If you would have told me that BYU would go into The Kennel and come out with a victory despite shooting 17.6 percent from beyond the arc (including missing on 13 consecutive 3-point attempts at one point), allowing Bulldogs star Kyle Wiltjer to go wild and score 35 points, and Cougar freshman phenoms Nick Emery and Zac Seljaas combining for a measly 5 points, I would have recommended you consider having your head examined.

But that actually happened. Like, in real life.

The question, of course, is how? How did the Cougars pull off such an improbable win? And what can be gleaned from it and replicated to ensure similar success in the face of such obstacles in the future?

In hindsight, there are a number of possible answers to those questions. For one, Chase Fischer repeatedly attacked the basket like a man possessed rather than settling for long jumpers on a cold shooting night, which helped BYU survive an otherwise anemic offensive first half. Similarly, Kyle Collinsworth bounced back from foul trouble in the opening frame to put the team on his shoulders and bring the Cougars back from the brink through pure physical dominance after the break. And of course, Nick Emery showed his incredible confidence by hitting his only bucket of the night when it mattered most and Nate Austin ultimately swooped in to save the boys in blue's butts by blocking everything in sight in the closing seconds.

All of those things contributed to BYU's unlikely victory — but one other factor probably rises above the rest in terms of explaining the unexplainable:

BYU played good team defense! No, seriously.

This is perhaps the most important reason for BYU's success in Spokane. It's no secret that the Cougars have struggled to stop (or even mildly irritate) opponents on the defensive end in recent years, so when their offense goes missing like it did for long stretches on Thursday, they tend to lose.

That wasn't the case against the Zags. BYU held the home team to a respectable 68 points. That's not a Big Ten-level defensive number, but in the wild West Coast Conference — and especially for BYU — that's pretty good. If the Cougars could figure out how to consistently hold opponents under 70 points, they would be very tough to beat.

But wait, you might be thinking. Didn't you say that BYU gave up 35 points to Kyle Wiltjer? How is that good defense?

To be fair, that wasn't necessairly great, but it also seemed to be planned. Let me explain.

Wiltjer is a great player who is almost assuredly going to score 20-30 points on you every time out, no matter what you do. You can double- or triple-team him, and he's still likely going to get his — perhaps not 35, but he'll find ways to score nonetheless.

The problems can start when you choose to send those additional defenders, because Wiltjer is a smart enough player to recognize and exploit the double-team, finding open teammates with the pass and forcing the defense to over-rotate to compensate. At this point, the defense's shell is compromised. It only takes a small amount of ball movement to find someone open for an easy bucket.

BYU's coaches seemed to recognize this issue and made an interesting strategic decision: they rarely, if ever, brought an extra defender to help on Wiltjer. They resisted the impulse to double-team the All-American. This resulted in him getting a few better looks than he might otherwise get as he spent more time with the ball in his hands in one-on-one situations, but also allowed the Cougars to stay home on the Zags' other players and minimize the need for additional rotations. This reduced the number of uncontrolled closeouts on open shooters (a serious and persistent weakness for BYU), which in turn resulted in fewer opponents blowing by a compromised defender and getting a free pass to the paint.

By staying home on the other Bulldogs, BYU essentially dared Wiltjer to beat them single-handedly. And he turned in an incredible performance in his own right. He's a great offensive player and a tough one-on-one cover for even the stingiest defender. But the Cougars made a calculated gamble that they could risk giving up 35 points to one guy, so long as they limited everyone else. And it worked. While a succession of individual defenders tried their best to at least slow down Wiltjer mano a mano with expectedly poor results, the rest of the team maintained the integrity of its defensive shell and forced other players into tough shots that rarely converted.

As a result, the non-Wiltjer Zags combined for only 33 total points on 29.4 percent shooting from the field. Additionally, BYU surrendered only 20 points in the paint to the frontline-heavy Zags — the lowest number they've given up against a Division I opponent since the season opener. (This was, admittedly, helped by Domantas Sabonis' chronic foul trouble, but that fact shouldn't and doesn't discredit the end-result.) And because they maintained their defensive positioning, the Cougars were able to more effectively contest perimeter looks, holding the non-Wiltjer Zags to just 16.7 percent shooting from beyond the arc.

No matter which way you slice it, this was a smart, focused and deeply impressive defensive performance at a time when the Cougars badly needed one. This is what the vaunted "Pack Line" defense is supposed to look like — limiting the need for over-helping, constantly walling off the paint from penetration, and staying in position to allow for controlled closeouts that contest outside looks. It took 17 tries, but BYU finally put it all together for at least one game.

The big question now, with a potentially season-changing win in The Kennel under their belts, is whether they can do it again.