Sometimes a change of opinion comes about when one is presented with new evidence, when detailed research sheds new light on an old subject. And sometimes it just happens because the wait for the NFL draft is absolutely too long.

I can't tell you which one applies here, but I have jumped on board with the idea of the Cowboys drafting Ohio State running back Ezekiel Elliott with the No. 4 pick Thursday night. I think it's the best way to fix a defense that needs considerable help.

Yes, defense.

I was never against taking Elliott for anything related to his skills. At Ohio State, winning the national championship here at AT&T Stadium and then playing at a high level again in 2015, he looked the part as a runner, as a receiver and as a man who finds the end zone (41 times the last two years).

My hesitation was based on the fact that this team can get considerable production from Darren McFadden (1,089 rushing yards in 2015) and presumably Alfred Morris because of the size and strength of this offensive line. Why not fix the defense with that highest pick, now that quarterback has been eliminated by the Rams and Eagles trading up?

The reality is that one player -- cornerback Jalen Ramsey or defensive end Joey Bosa -- would certainly stand to upgrade the team's weaker unit. But by how much exactly?

Ramsey was so highly thought of at Florida State that he had just one interception last year. Quarterbacks didn't throw his way. At least that's the explanation. As for Bosa, do you have to worry about his one-game suspension at the start of 2015 for refusal to take a drug test?

On this team, with two defensive ends already facing four-game suspensions to start 2016, is the addition of Bosa a toxic idea?

Maybe there are no significant reasons to be concerned about either of these players. But here's what we know: If Elliott arrives and runs behind this line as he would seem capable of doing -- think DeMarco Murray in 2014 -- how high a level does this offense reach with the return of Tony Romo and Dez Bryant?

And, ultimately, that's how you go about fixing this defense. You construct an offense that scores 30 points a game and dare opponents to keep up.

That's what the success of the 2014 season was all about. The Cowboys want to get back to those 31 takeaways the defense produced that season, second only to Houston. The best way to do that, the surest way isn't to draft Bosa or Ramsey.

It's to take the lead on the field week after week and force opponents to throw the ball.

That's what happened in 2014. Do you think some light bulb went off over linebacker Bruce Carter's head that enabled him to intercept five passes that season?

Carter had none his first three years in Dallas. He had none last year for Tampa Bay after cashing in on those five picks with a free-agent deal.

You get out ahead of your opponent, you force them into situations that are uncomfortable and you create turnovers. I don't doubt that Bosa or Ramsey could help a little. But what if Elliott helps a lot?

Cowboys owner Jerry Jones indicated this week that Elliott remains a consideration.

"Just because we didn't do [re-sign] Murray, just because we have running back by committee doesn't mean at all we're not in the running back business,'' Jones said. "There's a ton of difference of putting [money] on the back who's had no carries and is fresh than on one who's had five or six years. That's just life.''

Cowboys vice president Stephen Jones called Elliott "a top-10 pick."

But is he top four? Or do the Cowboys feel they can trade down a few spots and still land him? The concern there is the New York Giants sitting at 10. That's a team that spent huge free-agent dollars to rebuild its defense but hasn't had a quality running back the last few seasons.

You wouldn't want to get cute in trading down and then see Elliott land with the Giants.

So the smart, safe move is simply to take Elliott at four. Who cares if some folks think that's too high for a running back these days? He won't be turning into Trent Richardson behind this offensive line.

Invest in offense. That's the surest way to ignite a dormant defense.

Twitter: @TimCowlishaw