CHRIS CODUTO/Arizona Daily Wildcat Arizona defensive lineman Carlos Williams hangs his head during the waning moments of the Wildcats' 37-17 loss to UCLA Saturday at the Rose Bowl in Pasadena, Calif.

PASADENA, Calif. - The numbers never lie.

Almost.

The UA defense held UCLA's two-headed backfield monster of Manuel White and Maurice Drew to just 44 yards combined in the first half, on 14 carries. Arizona's own formidable backfield combination of Mike Bell and Gilbert Harris hit the holes for 144 yards on 19 carries through two quarters.

Arizona's offense held onto the ball four and a half minutes longer than UCLA. The Wildcats gained 9 first downs to UCLA's 11, and 172 total yards to the Bruins' 189.

Yet the game was all but decided by halftime, with the Bruins' cruising to a 23-3 lead.

How can that be?

The Wildcats' ability to convert just one of six third down attempts and the fact they were penalized nine times for 83 yards might have something to do with it.

"I thought our game plan was pretty thorough and we played pretty good, preparing for two weeks," said UA offensive coordinator Mike Canales. "But it comes down to execution and we didn't execute."

What started out as an early-season aberration of the potential of the Pacific 10 Conference's worst team last season has developed into a stigma that has few teams in the Pac-10 truly worried when it comes down to playing Arizona.

Teams have been able to hang their hats on the fact that, at some point over the course of a 60-minute game, the Wildcats will beat themselves.

"I thought our team played extremely hard, but we didn't play very smart tonight, and that hurts us," Stoops said. "Our execution, in fundamentally catching the football - we dropped three touchdowns - is not something we're good enough to overcome at this point."

The Wildcats dug an early hole against Utah last month with a Mike Bell fumble on the game's first play from scrimmage, before losing a pair of close games to Wisconsin and Washington State, on a missed field goal late and a costly late-game fumble while trying to preserve a lead.

Arizona's loss to UCLA Saturday can be pinned to the Wildcats' first drive of the game, a four-play, two-minute sequence - including a Bruin sack of UA quarterback Kris Heavner, a delay of game by Arizona and an uncommon offensive facemask penalty - that led to a blocked punt out of the back of the end zone for a UCLA safety.

UCLA scored a touchdown on its subsequent drive to lead 9-0 and never looked back.

It doesn't matter that Arizona virtually shut down UCLA's duo of the Pac-10's first and third leading rushers, or that the Wildcats ultimately out-gained the Bruins by 140 yards on the ground, and by three overall.

Winning the stat battle is meaningless if a team can't win the game.

Costly mistakes - whether on the game's first series or the team's final drive - has hurt Arizona this season, not an inability to move the ball downfield or win the time of possession war.

Dropping wide-open passes, accumulating penalties at alarming rates and special teams breakdowns - all of which plagued the Wildcats Saturday - are anything but conducive to winning football games.

"It's just uncanny. We got an interception and they go down and score the next drive," Stoops said. "We have them stopped on third and 15, get called for holding, and they score the next play. It's just really frustrating."

Unless the Wildcats can figure out a way to single out and eliminate those random miscues, Stoops is likely to become more frustrated because the only numbers that matter so far this season –-a 1-4 overall record - are likely to get worse over the next six games.