The Dallas Cowboys came to Seattle with the 20^th-ranked run defense in the league. You would think the Seahawks would have tried to exploit that weakness using their top-ranked rushing offense.

But, the same Seattle offense that ran for 225 yards on 36 attempts against Washington on Monday chose to eschew the run Sunday in a 30-23 loss. Coach Pete Carroll blamed it on losing the third-down battle, but it certainly was more than that.

True, the Hawks won just 12 of 30 third downs on both sides, which led to a 38-22 edge for Dallas in time of possession. And the defense gave up the biggest conversion — on third-and-20 — with five minutes left.

But the Hawks could have run the ball more than 18 times. Marshawn Lynch carried it just 10 — even though he averaged 6.1 yards per tote. Russell Wilson, who ran for a career-best 122 yards on 11 carries last Monday, ran it just twice for 12 yards vs. Dallas.

“We weren’t making first downs. You have to get the rhythm,” Carroll explained. “(People ask) ‘Why didn’t you give the ball to Marshawn more? Or why didn’t this guy catch more passes?’ It’s because you have to get first downs and get more plays. When the defense is out there for a long time and the offense has a three-and-out, then you don’t get your shots. The story is going to write itself every time that way.”

But what led to those three-and-outs? Most people think it was a distinct lack of Beast Mode.

The lack of run calls was somewhat ironic just a few days after offensive coordinator Darrell Bevell said, “You don’t have to be explosive through the air. Our runs are explosive (too).”

Despite limited chances, Lynch proved him right — busting off a 32-yard run in the third quarter. But Lynch was not seen again on that drive, which fizzled out just three plays later.

“We tried to come back and get back in the rhythm,” Carroll said. “Marshawn did a nice job, popped a run and got some stuff going. He was busting his tail to help us, but we just couldn’t get in sync and get the rhythm and connect it with the third-down conversions.”

One of the problems was the Hawks were almost never in running downs on third down. Of their 13 third downs, only one required five yards or less to convert, and Lynch ran for five yards on that third-and-4.

It all starts on first down, and the Hawks never gained more than five yards — until Wilson hit Luke Willson on a 10-yard pass at the end of the game (Wilson threw a game -ending interception right after that). You can put some of that on Wilson’s poor play, but the rest goes to Bevell for not sticking with the run and changing it up when he saw what was not working.

Wilson threw the ball 28 times and completed just 14 — easily his worst passing game of the season and one of his three worst games in the last two years.

Wilson took full responsibility for an off day: “I’ll take the blame for it. I could have played a lot better. … I was a little off on some throws that I’m normally not.”

Yeah, Wilson was bad Sunday. But — more than that — this game was an extension of a season-long trend in which the offense has been terrible in the second half. It was a problem heading into their bye, and they have not fixed it.

In their past four games, they have scored on just three of 19 second-half drives that started in their own territory. (In the first half, they have scored on eight of 19 drives that began in their territory.)

The blame for this loss universally has been laid on Bevell for not running the ball, for getting too cute with personnel, for not getting the ball to Percy Harvin beyond a few runs that went nowhere.

It has become very clear that the Hawks need to go back to their bread and butter — Lynch — and stop trying to spread the ball around to lesser players. When Wilson is going to No. 5 receiver Bryan Walters in key situations, there is a huge problem with the offense. And that is on Bevell.

Last year, Bevell failed to scheme well enough to protect Wilson behind an inferior line. This year, Bevell has been too cute, using Harvin as a decoy far too much, failing to run Lynch enough, utilizing tertiary players at key points in games.

Against Dallas, Lynch carried the ball on consecutive plays just three times. His combination of yards on those plays: 36, 11, 6. Why not do it a few more times?

And Harvin had another head-scratching game. Six days after having three touchdowns called back vs. Washington, Harvin netted minus-1 yard on six touches (three runs, three catches) vs. Dallas.

Owner Paul Allen and GM John Schneider are probably thinking, along with the rest of us, “That is not what we paid Harvin $67 million to do.”

The Hawks are 3-2 — the same start they had in 2012, when they finished 11-5 and came 30 seconds short of the NFC title game. Their two losses — both winnable in the fourth quarter — have come against San Diego and Dallas — teams that are off to 5-1 starts. The season certainly is not over.

But the Hawks have to get their offense going in the right direction. They have a prime chance to do it next Sunday in St. Louis. The Rams are giving up 152 rushing yards per game. Will Bevell give Lynch the ball like he should have against Dallas?