BOULDER — Sunday evening’s game between the Colorado Buffaloes and the Oregon State Beavers was vanilla for the first 30 minutes.

Colorado, the more talented team, simply out-played Oregon State. There wasn’t a 3-point barrage, or a dominant individual performance, or a lockdown defensive effort. The Buffs just put in a B-level defensive effort and a B-level offensive effort, and that was enough to build an 11-point lead with under eight minutes left on the clock.

There was nothing all that special about it.

Then, Oregon State made a switch.

“[Associate head] coach [Mike] Rohn was telling us the whole half, when we had that 10 point lead, that it would come at some point,” star Buffs point guard McKinley Wright IV said after the game. “We just didn’t execute.”

Colorado practiced against the 1-3-1 Zone Defense Saturday afternoon, the day before the game. The Buffs knew it was a weapon in the Beavers’ arsenal and that it was likely to be deployed at some point during the game.

“They were down 10 with five minutes to go and they said ‘well let’s throw this out there and see if they can handle it’, and we did not handle it,” Buffs head coach Tad Boyle said.

The 1-3-1 zone isn’t impossible to beat. In fact, it isn’t all that hard to beat at all.

“I don’t mind playing against the 1-3-1,” Boyle said. “I’ve done it, I’ve coached against it many times and have never had something like this happen to a team.”

So what exactly went wrong?

Colorado stopped playing aggressive offense

This is the biggest problem.

The easiest way to beat a zone defense is to pressure the gaps between the zones. Either the ball-handler splits the defenders and drives to the rim, or he draws a double-team and can move the ball to whoever is left open.

Instead of taking what they could from the defense, the Buffs held back and tried to drain the clock, giving the defense a chance to trap them. When Colorado did force the issue, its ball-handlers weren’t quick to make a pass, instead getting tied up in the double-team.

“It’s just ‘Basketball 101,'” Boyle said. “Two guys are guarding you, move the ball, attack the gap, move the ball back. If you do that two or three times, that’s all you have to do against it.”

When the Buffs moved the ball into the corners, the Beavers trapped it. Colorado could have driven quickly when the ball got to the corner to beat the trap, or just moved the ball when the double-team was on the way, but the ball-handler often waited too long and got pinned in the corner by two defenders.

“You have to catch it in the corner and drive before the trap gets there,” Boyle said. “Those are the things we worked on and talked about in practice, but when it came tonight we didn’t do it and you got one of the most disappointing losses.”

The lack of aggressiveness could have come from a few different places; Colorado could have been trying too hard to burn clock instead of trying to score points, it could have been confused by what the defense was doing and too slow mentally to take advantage, or it could have just been lazy.

Whatever the cause, the lack of offensive energy was a major problem late in the game.

The Buffs couldn’t handle the press

The offensive woes didn’t start in the half-court sets.

Of the Buffs’ nine turnovers in the last nine minutes of the game, three came before the ball even crossed midcourt.

When the Beavers switched to their zone defense, they also began pressing the Buffs’ ball-handlers. Colorado couldn’t carry the ball up the court without resistance, and it struggled.

“We saw the soft press against Oregon. All night we handled it well,” Boyle said. “They threw it against us tonight and we didn’t handle it well.”

Colorado’s turnovers also led to easy transition points for the Beavers, neutralizing the Buffs’ best asset: its defense.

The play that likely doomed the Buffs came with a minute left in the game. The Buffs trailed by three and Wright tried to carry the ball up the court. He worked fairly nonchalantly as if he wasn’t concerned by the press. Then, he had the ball wrestled away and the Beavers earned two free throws off of a foul to stop the break.

All of a sudden, there was a five-point deficit with 57 seconds to play and the odds had shifted dramatically in the Beavers’ favor.

Colorado couldn’t take advantage of the zone’s Achilles heel

There are plenty of flaws to playing zone defenses but one stands above the rest: It makes rebounding difficult.

In a man defense, each defensive player is matched up against one offensive player. The defender stands between the offensive player and the basket. When it comes time to rebound, the defender is in good position to box out.

But the 1-3-1 zone leaves just one inside defender working under the basket. That means, at the end of the possession, it’s tougher for the defense to box out. Typically, there are offensive players unaccounted for. Offenses typically get more second-chance opportunities.

“But in order offensive rebound, you have to get shots, and we couldn’t,” Boyle said.

That’s a pretty simple point, but it explains how Colorado’s offensive struggles spiraled.

Not only did not putting shots up due to turnovers mean there were fewer opportunities to see the ball go through the net, but it also meant there were significantly fewer possessions to generate shots. Colorado failed to take advantage of the Beavers’ most vulnerable weakness.

Final Thoughts

Quite a few pieces have to come together to create a 24-5 run, and that’s exactly what happened Sunday evening.

Oregon State found a way to neutralize Colorado’s greatest strength; it forced turnovers so that the Buffs’ defense couldn’t get set up.

Colorado couldn’t take advantage of the Beavers’ weakness; their lack of rebounders under the basket defensively.

Pretty much everything that could have broken wrong for the Buffs did, and it’s mostly their fault for not being prepared, despite working on attacking a 1-3-1 Zone the day before the game.

“We thought we had a good feel for it but I guess it wasn’t good enough,” forward Evan Battey said after the game. “We beat ourselves.”

Now, a potential roadmap to beat Colorado has been broadcast to the entire Pac-12 and it’s up to the Buffs to fix all that went wrong on Sunday.

“We’re playing in Corvallis sometime in February, and my guess is we’re going to see the 1-3-1 zone,” Boyle said. “I’m not a rocket scientist but my guess is we’ll see it. We better handle it better than we handled it tonight.”