There's one easy explanation why the Arizona Wildcats went 8-3 in games decided by five points or less last season.

That, of course, would be Derrick Williams.

You know: The blocks against Washington (87-86) at home and Memphis (77-75) in the NCAA tournament. The three-point play against Texas (70-69) in the tournament. And the monster regular-season games he had at Washington State (65-63) and against Cal at home (73-71).

Arizona is only 1-5 in games it has trailed with five minutes to go this season. But, as UA coach Sean Miller has noted a few times, Williams "is not coming back."

So, while Miller says the Wildcats again will inevitably need to close out a number of difficult games if they are to succeed, Arizona is likely to need even more help from forward Solomon Hill and his teammates.

Over the final five minutes of UA games this season, Hill has proven the most clutch late in games. He leads the Wildcats in scoring (2.2 points) and rebounding (1.7) while he's shot 52.9 percent from the field and made 86.4 percent of his free throws in the final 5:00. He's also grabbed a third of his 15 steals then.

But the Wildcats are shooting a collective 28.9-percent from three-point range in the final five minutes and have more turnovers (35) than assists (32) in that timeframe. Freshman guards Nick Johnson (2 of 10 threes) and Josiah Turner (23.1 percent overall from the field) have had jittery shots, too.

As a possible result, Arizona is 0-2 in games decided by six points or less this season and 1-1 in overtime games decided by more than five points.

"So much of it comes down to being able to finish," Miller said last week. "Last year (at home) Cal wasn't having the season we were having, but we had to make about three plays at the end.

"For our team this year, we don't have a lot of margin for error. We're always going to be in these hard-fought games, and being strong at the end of the game is an important quality to have."

Rim shots

• The Wildcats' official RPI dropped from 53 to 64 after their loss to Oregon on Saturday.

• Washington's Terrence Ross was named the Pac-12's player of the week after averaging 21.0 points and 10 rebounds in the Huskies' wins over Seattle and Washington State last week. Ross had 30 points against WSU.

• Colorado coach Tad Boyle, whose Buffaloes will host Arizona on Saturday, said his team looked "mediocre" after getting swept at Cal and Stanford over the weekend. "Until we learn to win on the road, we're going to be in the muck," he said after a 20-point loss at Stanford. "And we don't want to be in the muck."

Who delivers most in the clutch?

Some average percentage comparisons between Arizona players in the first 35 minutes and the final five minutes through 18 games this season:

Player, stat, last 5 min, first 35

Solomon Hill FT 86.4 69.8

Nick Johnson 3PT 20.0 38.4

Jesse Perry FG 72.2 50.7

Kyle Fogg FG 52.9 38.8

Brendon Lavender 3PT 40.0 60.0

Jordin Mayes 3PT 42.9 32.0

Josiah Turner A-TO ratio 2-1 0.9-1