This is the second in a two-part series analyzing the first half of the Arizona Wildcats’ football season. This installment examines the defense.

Has the Arizona Wildcats’ rebuilt defense been perfect? No. Of course not.

But all things considered, the unit’s makeover — which has been almost two years in the making — has to be considered an unqualified success.

The Cats are giving up fewer points. They’re taking the ball away more. The defense has played just as big a role in Arizona’s surprising first half as the offense.

UA coach Rich Rodriguez is getting what he hoped for when he turned over the defensive staff after the 2015 season. Led by defensive coordinator Marcel Yates, those coaches have brought in quality players and helped the returning players improve.

“We’re not where we need to be,” Yates said Wednesday. “(But) I think we’re getting better every week.”

Arizona’s defense simply wasn’t good enough last year. (To be fair, the Wildcats’ offense and special teams struggled as well during a 3-9 campaign.) Through six games, it has progressed in every conceivable way.

Points against are down from 38.3 per game to 26.8. Total yards are down from 469.3 to 410.7. Opponents’ third-down percentage has fallen from 52.6 to 43.7.

But two numbers stand out the most.

The first is three-and-outs. Arizona forced 30 three-and-outs last season, or 2.5 per game. The Wildcats already have 25 this year – 4.2 per game.

The second is takeaways. Arizona has forced 13 turnovers in six games – just one shy of last season’s total. During their eight-game Pac-12 losing streak last year, the Wildcats took the ball away only four times while giving it away 18 times. That’s a surefire recipe for defeat.

“We’ve been giving up too many points, too many yards,” junior cornerback Jace Whittaker said. “But we still are causing turnovers. That’s what we gotta keep doing.”

Arizona had a season-high four takeaways in last week’s 47-30 victory over UCLA. Whittaker had two interceptions – one in the end zone and one he returned 42 yards for a touchdown.

The Wildcats held Bruins star quarterback Josh Rosen without a touchdown, providing more than enough support for an offense that continued to hum along behind QB Khalil Tate. The performance was particularly noteworthy in that it followed the defense’s worst outing of the season.

Arizona surrendered a season-high 42 points the previous week against Colorado. For most of the game, the Wildcats couldn’t get the Buffaloes off the field. Rodriguez wanted the Cats to learn from that experience, and they did.

“We made some corrections from the week before. That’s all we ask,” Rodriguez said. “We know it’s going to be a work in progress at times. A couple games we didn’t play well at all. But the last game we got better than the week before, and that’s a nice sign.”

Rodriguez expected some rough patches with so many rookies in the lineup. The past two weeks, Arizona has started four true freshmen on defense: linebackers Tony Fields II and Colin Schooler; “Stud” Kylan Wilborn; and free safety Scottie Young Jr.

Fields, Wilborn and Young have started every game this season. Even when he wasn’t starting, Schooler was playing regularly. Add redshirt freshman cornerback Lorenzo Burns to the mix, and nearly half of Arizona’s defense consists of freshmen.

Burns, Fields and Young rank 1-2-3 on the team in tackles. Wilborn leads the squad in tackles-for-losses, sacks and forced fumbles. Schooler is tied for second in TFLs with Fields, Young and senior safety Dane Cruikshank.

“When Coach Rod says he wants guys with a hard edge, that’s what this recruiting class was,” Yates said. “We recruited a bunch of young guys that came from winning programs that have that hard edge. You don’t hear them complaining. They run to the ball. They love football.

“His message was clear what he wanted on this football team. They all fit that mold. They want to hit people. I love it.”

While the newcomers have infused the defense with talent, the veterans are playing with a greater comfort level in Year 2 under Yates. As Cruikshank put it: “We understand our job and what we’re supposed to be doing.”

If there’s an area of concern, it’s stopping the run. In the first four games, Arizona allowed 118 rushing yards per contest. Colorado then piled up 300. Tailback Phillip Lindsay rushed for 281 of those yards, with 187 coming after contact, according to Pro Football Focus.

UCLA followed up with a season-high 190 yards. The Wildcats’ game plan was geared toward rattling Rosen. They knew they would give up some yardage on the ground. Just not that much.

“We’re not overly big,” Rodriguez said. “When you’re undersized, you have to play with great leverage and make sure you have gap integrity. At times our run defense has not been as good as it’s needed to be. The Colorado game wasn’t good at all. This last game there were a couple drives where there wasn’t much resistance. We’ve got work to do.”

Yates expects Arizona’s opponents, starting with Cal on Saturday, to pound away at the Wildcats’ relatively undersized defensive front and take shots in the passing game. That’s been Arizona’s M.O. on offense the past two weeks, and it has worked.

That ground battle, on both sides, likely will determine the Wildcats’ fate in the second half.

Extra points

  • Tate was named the quarterback on Pro Football Focus’ National Team of the Week for the second week in a row.
  • Freshman Troy Young is expected to start at the “Bandit” safety spot in a slightly reconfigured secondary. The usual Bandit, Demetrius Flannigan-Fowles, would shift to free safety in place of Young Jr., who is unlikely to play because of a knee injury.
  • Arizona is 2-0 on the road. Rodriguez has been pleased with the maturity of the young players, who have handled those away games as “business trips,” he said.
  • With former UA assistant Charlie Ragle on the Cal sideline, Rodriguez said the Wildcats might make a few adjustments with their signals and terminology.