In the Seattle Seahawks' Week 2 win over San Francisco, the defense played a very good game for the most part, limiting the 49ers to just nine points. But thanks to a couple of big plays, most notably a 61-yard run, 49ers running back Carlos Hyde was able to gain 124 yards on 15 carries.

A week later, Tennessee's DeMarco Murray went for 115 yards on 14 carries against Seattle, with most of the damage again coming on one play, this time a 75-yard touchdown run. For a defense that prides itself on not giving up big plays, those performances were tough to stomach for the Seahawks defense, which a year earlier held opposing rushers to a league-low 3.4 yards per rush.

Short of winning the turnover battle, perhaps no stat is more important to Seahawks coach Pete Carroll than explosive plays, which the Seahawks and many other teams define as runs of 12-plus yards and passes of 16-plus yards. There is pretty significant data that shows that those explosive plays greatly increase the odds of scoring on any given drive, so for a defensive-minded coach like Carroll, seeing his defense give up huge running plays was painful, to say the least.

"You have to stop big plays from happening," Carroll once said. "You're not worth a darn on defense if you're giving up a bunch of explosive plays. What are you doing? The whole thing is to slow the thing down and give yourself a chance to stop people. The big plays are so significant in terms of scoring opportunities in terms of drives itself. That's a major factor."

Well since those two rough outings against San Francisco and Tennessee, the Seahawks' run defense has been worth a darn, and then some. After allowing a league-low 17 explosive runs last season, the Seahawks have been on a similar pace since that Week 3 loss in Nashville, giving up eight in seven games. And since Murray and Hyde eclipsed the 100-yard mark in back-to-back games, the most any running back has gained against Seattle was Lamar Miller's 21-carry, 54-yard performance Houston's Week 8 loss to the Seahawks. During that seven-game stretch, the Seahawks are allowing just 3.2 yards per rush, the second best mark in the league, and 80 rushing yards per game, which ranks third.

Undoubtedly the Seahawks' considerable talent on defense contributes to their success in the running game, but when they're really on their game, what makes the biggest difference is the discipline to do things right play after play after play so that one big run doesn't pop at some point in a game.

"The run defense is really about disciplined play," Carroll said. "You got to have good players and all, but if you don't do right, then you can't be consistent. You can have spurts where you are good and you can be effective and get guys in the backfield at times with pressures and things like that, but to play really good run defense over a really long time, you have to be disciplined and you have to keep maintaining your gap control and relative spacing and all of the principles. Then if your players are good and make plays and defeat blocks, then you can be really good at it. It starts with the discipline of the scheme. If you are jumping around scheme-wise, you are lucking out. So we have been committed for a long time to be really consistent there, and it has generally worked out. That is why it is so hard for us to stomach the thought that we gave up four or five plays a game that are explosive run plays or whatever. We've just been really committed to it and for the most part, it's worked out."

So what changed between those early season games and now?

"I think it's being a little bit more disciplined," linebacker Bobby Wagner said. "I think we're playing more gap-sound, and guys are shooting gaps. It's just us making plays and being on the same page. Communication has gotten a lot better, and discipline has gotten a lot better; we're not really hurting ourselves like that. We're just locked in and focused.

"We take a lot of pride in (our run defense). That's one of the things you want to do, you want to stop the run, force a team to pass, and we feel like we've got the playmakers on the back end to take care of the passing game. That's the first thing we want to do in every game is stop the run."

And it's not just Carroll who abhors giving up big running plays; those were very tough for the players to see happen as well.

"At the beginning of the year, we were giving up 60-plus-yard runs, and that wasn't like us," defensive end Frank Clark said. "For as long as I've been here, and for as long as I've had knowledge of the Seattle Seahawks, this defense in Coach Carroll's era, that's not what I've grown comfortable seeing. So to see it happen to us early on in the year was kind of a shock, and it was immediately adjusted."

Now, with the Seahawks set to face Hyde and the 49ers again on Sunday, Seattle's defense is looking to show once again that it is past its early big-play issues.

"We gave up, what 125 yards to him last time?" Clark said. "He had a huge run on a play where we looked like not the Seahawks defense we're accustomed to, where we missed a lot of tackles. One thing we want to do, we pride ourselves on having a great run defense, and this time around we get a second opportunity to put that on display, and that's what we're going to do."