NORMAN — Through four games, Brent Venables has seen the same thing as everybody else.

The Oklahoma defense is simply playing at a higher level than it was last season.

The improvement is obvious by just watching the team. The Sooners have surrendered just 8.5 points per game, the second-best mark in the entire country, and have only allowed three touchdowns so far this season.

But Venables believes the Sooners aren’t close to how good they can be.

“We’ve got a long ways to go,” Venables said during his Tuesday press conference. “I have great appreciation and respect for the improvement our guys have made, which we have been talking about for sometime now, that we have seen improvement. But they’ll be the first ones to tell you if they stood up here, there’s evidence that there’s been some improvement but nowhere close to a finished product… Let’s see where we’re at at the end of the year.”

Here’s a look at a few of the Sooners’ notable defensive stats through four weeks:

Venables and the coaching staff preached all offseason about the need to improve on third downs. Opponents converted on nearly 41% of their third-down attempts a year ago, one of the highest percentages in the country.

So far, the Sooners have shown tremendous improvement. Opponents have converted 17-of-62 (27%) third-down attempts, which ranks 11th nationally and second in the Big 12.

For comparison’s sake, the Sooners’ surrendered a conversion rate of 38% (25-of-65) through four games last season.

“Guys that are returning (are) a little more knowledgeable, a little more confident, a little more aggressive within the scheme,” Venables said when asked by OUInsider. “(They’re) a little more precise in the scheme, because of the knowledge, so our ability to execute with a little more precision is there. As we said, we’ve improved our strength and our speed, our explosiveness with players that are on the roster.

“It’s not just a couple of things. It’s about everything, and the third-down area is a byproduct of small, incremental improvement in a lot of areas.”

What a difference a year makes. This season, the Sooners have allowed just 95 rushing yards per game, which rank 21st nationally. They’re also surrendering just 2.7 yards per carry and haven't allowed a rushing touchdown this season. The biggest example of improvement came last Saturday when the Sooners limited Cincinnati, which was averaging nearly 240 rushing yards, to just 141 yards on the ground.

Last season, the Sooners allowed 187 rushing yards per game and 157.5 through the first four games.

The impressive part is that OU’s opponents are running the ball on 48.6% of their plays, per Team Rankings, which is comparable to last year’s mark of 50.84. Essentially, the Sooners are still seeing a heavy dose of rushing attempts. They’re just playing much better defense.

Opponents averaged an astonishing 5.6 yards per play a year ago. Whether it was through the air or on the ground, the Sooners’ defense surrendered big play after big play.

That simply hasn’t been the case so far in 2023. The Sooners have allowed just 4.3 yards per play, tied for 13th nationally along with teams like Alabama, Georgia and Texas.

That’s reflected in the total defense data. OU’s giving up 310 yards per game, which is 26th nationally and a far cry from last year’s number of 487.

Passer rating can be a tricky stat to calculate. But this is the formulate that’s used to generate a quarterback’s passing efficiency:

NCAA Passer Rating = ((8.4 x Passing Yards) + (330 x Touchdown Passes) + (100 x Number of Completions) – (200 x Interceptions)) ÷ Passing Attempts

This formula is used to boil down a quarterback’s performance into one number. The number can range from -731.6 to 1,261.6.

The Sooners’ passing defense has improved from last year, as they’re surrendering 215.5 passing yards per game compared to 273.5 last year. But what they’re really doing well is limiting the efficiency of opposing quarterbacks. The Sooners rank 10th nationally in average opponent passing efficiency (102.3). Last year, opposing quarterbacks posted an average efficiency of 128.2 against the Sooners.

A big reason for that is interceptions. The Sooners already have eight interceptions this season compared to three at this point last year. They've also only surrendered three passing touchdowns.

The Sooners still have eight regular-season games to go, and they haven’t faced their toughest tests to this point. However, as Venables acknowledged, the Sooners are playing well, and the stats back it up