TEMPE, Ariz. -- Moments before Arizona Cardinals quarterback Kyler Murray called for the snap on first-and-goal from the 9-yard-line late in the fourth quarter against the San Francisco 49ers, he saw something that rarely happens: wide receiver DeAndre Hopkins facing one-on-one coverage.
The Cardinals had four receivers on the field -- three to Murray's left, with Hopkins the farthest one wide, and one to his right. Murray quickly checked into a different play. The lone safety on the play, San Francisco's Jimmie Ward, watched Murray tell his offensive line and running back James Conner what the new play was going to be, and then began to shade to the lone receiver to Murray's right, A.J. Green.
Murray took a two-step drop and fired the pass toward the front left corner of the end zone. Hopkins went up and over 49ers cornerback Josh Norman to snatch the ball and put the Cardinals ahead 17-7.
The play was an example of Murray's deeper understanding of the Cardinals' offense and his ability to check in and out of plays, as well as another lesson on just how good Hopkins is.
It also showed how far the Cardinals' offense has come in the three seasons under coach Kliff Kingsbury. That look -- Hopkins against single coverage -- wouldn't have been there in either of the past two years. In this situation the play worked because of Murray, but Kingsbury's offense, as a whole, is working better than it ever has because he finally has all the players he needs.
"It's always going to be a process," Kingsbury said, adding that Cardinals general manager Steve Keim has "done a tremendous job bringing in some pieces, whether it's [wide receiver] A.J. [Green], [center] Rodney [Hudson], [rookie wide receiver] Rondale [Moore], who really complement what we have. And then Kyler's progression, just his understanding of the system, being able to get it to different people and not just look at one guy, has really helped it all come together so far."
The nuts and bolts of Arizona's offense this season don't differ much from a year ago. Air yards per target for receivers, tight end usage and motion is still low. The Cardinals still lead the NFL in four receiver sets and are among the teams using play-action the most.
There have been some small differences this season. The Cardinals are running out of four receiver sets more than in the past -- so much so that their 26 rush attempts with four receivers on the field are one less than all other 31 teams combined.
Arizona is also going deeper a little bit more often than last year and running more screen routes. The Cardinals had the lowest percentage of vertical routes the past two seasons. This year, they're up to 26th, and Murray has been quite accurate when he does go deep. He's completed 20 of 29 passes on vertical routes, giving him the highest completion rate (69%) in the NFL. He also leads the NFL in yards per attempt at 19.2 on vertical routes. At the same time, almost a third of the Cardinals' pass attempts -- 30% -- are either being thrown at or behind the line of scrimmage, which is the second highest rate behind the Eagles.
Even with those adjustments, personnel has been the biggest difference with a receiving unit led by Hopkins, Green, Kirk and Moore and a two-pronged backfield of Chase Edmonds and Conner.
"Every stop you go as a playcaller you're gonna adapt to your personnel and try to maximize what you have," Kingsbury said. "Then some stops you have a plethora of weapons and you got to try and take advantage of it and have great years when you do, because it doesn't come along that often that you have a group of wide outs like we have right now."
One of the main differences between this season and Kingsbury's first two is the balance. The top four receivers all have at least 261 yards and the difference between No. 1 and No. 4 is just 51 yards. A year ago, Hopkins finished with 786 more yards than the next closest receiver, meaning teams knew who to key on every single play. With this season's balance, the Cardinals make defenses pick who they can double, knowing what single coverage on another receiver can mean.
"The more weapons, the less you can do as far as doubling Hop, having a safety over there, or whatever it may be," Murray said. "You've got to respect everybody on the field, and I think we have that on our side."
Which is why Murray tried to take advantage of Hopkins receiving one-on-one coverage whenever he could on Sunday.
"You just have to give a guy like him an opportunity, you never know when there's two guys, three guys it doesn't really matter," Murray said. "Sometimes you screw the read, throw it to him and good things happen."
As elite as Hopkins is, he's also good with taking coverage away from his teammates.
"I would say this is my first time being on a team where there's other receivers that are reliably consistent, so, for me, that's great," Hopkins said. "It's just championship football, when you got four other guys that can go out there and take that pressure off of me and make plays [when] they're one-on-one."
The result of Keim's offseason additions -- all but Hopkins, Kirk and Edmonds are new to the Cardinals -- has been the sixth-best offense overall and the fourth-highest scoring team in the league (31.4 points per game).
Oh, and the Cardinals are 5-0 for the first time since 1974.
"It's been an evolution from the first year," Kingsbury said. "I remember the first few games we were in like in straight 10 personnel because it allowed Kyler to see it the best and play fast and do things he was comfortable with. And then last year we were able to progress and do some different stuff -- 12, 11 personnel, 13 personnel -- and then this year with some of those weapons, we're just able to continue to be creative and try to put guys in positions to be successful.
"But, that's kind of my mantra is just, 'Hey whatever we've got, let's maximize it make sure we're asking them to do things that they can do at a high level.'"