One-third of the 2010 Arizona football season is in the books, and the Wildcats couldn’t have asked for a better start — 4-0 and a No. 14 AP ranking.

Here’s a closer look at how each offensive position group has fared through four games:

Quarterbacks: A-

Junior Nick Foles has been nothing short of spectacular in 2010. He’s proven to be a “”big-time player,”” as running back Nic Grigsby described him, and has shown off poise well beyond his years.

The Iowa 72-yard game-winning drive followed by the 77-yard game-winning drive against Cal, have Foles’ name buzzing around the nation. The 6-foot-5, 245-pound quarterback currently leads the Pacific 10 Conference in completions (102), second in passing yards (1,089) and first in completion percentage (74.5), which is also third best in the nation.

Offensive line: B-

Aside from a forgettable performance against Cal on Saturday when it yielded three sacks and a ton of pressure, the offensive line has done its job in 2010. It’s a veteran unit led by center Colin Baxter that played a monumental role in defeating Iowa.

Left tackle Adam Grant held arguably the country’s best defensive end, Adrian Clayborn, to only zero sacks, and Iowa’s NFL-caliber front four were silent against the Wildcats.

But the O-line has allowed eight sacks through four games, which ranks sixth in sacks allowed in the Pac-10. The run game has also been mediocre through four games, which comes from the push of the offensive line.

Running Backs: C

The running game as a whole hasn’t gotten off the ground yet, but that was somewhat expected considering the pass-happy offense Arizona employs. When the Wildcats have run the ball, however, they haven’t been all that successful. The Wildcats are eighth in the Pac-10 in rushing offense, with 120.2 yards per game.

Senior No. 1 back Grigsby has been solid with a 5.6-yard average on 45 carries, to go along with five scores and a 62-yard touchdown run.

But all of Arizona’s eight rushing touchdowns came in the first two games, and it has yet to prove it can run effectively against an above-average defense. Keola Antolin, last year’s rushing leader, has struggled running but has 106 yards on 14 catches.

Wide Receivers/Tight Ends: B+

Despite losing Delashaun Dean and Terrell Turner in the offseason, Arizona’s receiving corps has impressed in 2010. The headliner Juron Criner has played out of his mind at times, especially in a 10 catch, 176 yard performance against Toledo.

He’s been limited with turf toe, but leads the team with 352 yards on 19 catches (18.5 average) and is on pace for a 1,000-yard season.

While Criner was supposed to be the big-play guy, the jury was still out on the rest of the receiving corps. But David Douglas has grabbed hold of the No. 2 role, as he’s second in the Pac-10 in receptions (22) and has become one of Foles’ favorite targets.

Bug Wright has done his job at inside receiver — 151 yards and two scores — while catching the game-winning touchdown against Iowa. David Roberts has also impressed as a No. 4 guy, with 10 catches for 123 yards.