PROVO — Pick your BYU/Colorado State nightmare or fantasy.

On the Ram side, it is receiver David Anderson running free as a deer, hauling in passes left, right and center; running back Kyle Bell ripping off 150 yards with quarterback Justin Holland standing untouched, completing 75 percent of his passes.

On the Cougar side, it is bombs to Todd Watkins, circus catches by Jonny Harline, bulldozer runs by Curtis Brown and Fahu Tahi, and John Beck completing passes like a robot to 12 receivers, sideline to sideline and the length of the field.

If one or both of the defenses fails to step up, that could be the picture tonight when Colorado State visits BYU.

The Rams and Cougars rank first and second in the league in total offense. The difference is a mere 13 yards per game, with CSU holding the advantage.

Both teams have proved capable of putting up big numbers. Both defenses have shown they can act as willing victims to good or even average offenses.

"Justin Holland threw for almost 360 yards against us last year with basically the same receiving corps and not as solid of a running game," BYU head coach Bronco Mendenhall said. "It's impressive to me that he's not a scrambler and he's only been sacked three times in five games, so I'm not sure you could address his durability.

"They are clearly protection-oriented and what you'll see is a very precise, accurate passer who delivers the ball before the receivers come out of their routes, with two- or three-man routes that are making breaks and double-moves at 15 to 22 yards downfield. Those are difficult to cover."

A year ago, Bell made his first career start against BYU. Now, he is a threat whom Mendenhall says runs harder late in the game.

The past two weeks, Mendenhall has retooled BYU's defense, picking the spots he will bring blitzes. He's changed coverages in his secondary. The return of corner Kayle Buchanan may give Mendenhall another corner for this game, if Buchanan can adjust his practice speed to game speed and execute.

Of his secondary, Mendenhall said BYU's execution has been more sound.

After giving up huge third-down plays at San Diego State in a loss, the Lobos had a tougher time converting, especially in the second half when BYU held the Lobos to just one field goal.

The Cougars have one interception this season. The Rams, on the other hand, have allowed seven passing touchdowns, three more than the Cougars. The Ram defense ranks 97th in the nation and allows 428 yards per game. BYU's defense ranks 78th, allowing 401 yards per outing.