Chris Vannini at coachingsearch.com crunched the numbers (http://coachingsearch.com/article?a=Chart-The-top-defensive-3rd-down-pla...). Hokies have allowed just 170 third down conversions on 586 attempts over the last three seasons. Bud Foster remains the best in the business.

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Is UVA that high because teams don't even go to third down that much....that record though.
Per the article, it is only a two year sample (along with the others marked with an asterisk). That said, extrapolated to a 3rd year, they would have 531 attempts, which is still on the low end of this group.
Yes, they are the only team on the list with a losing record over that time period.
But....uva, so.....
I approve this message.
Commence Mike London tears
A lot of very aggressive defenses who play a lot of tight coverage (low completion percentages). This is pretty much a who's who of defensive coordinators in college football.
Just imagine if Va talent stayed home, went to the good guys and let Torrian/Foster develop them. JUST IMAGINE IT DAMN IT! Sidenote: weren't UVA fans saying that they had the best 3rd down defense in the nation recently? Were they living a lie?
The reason this is a who's who is because 3rd-down conversion % doesn't measure third-down defense, it measures overall defense. If instead of using conversion percentage the list was average distance to go on 3rd down, the list would be virtually identical because the best way to have a low conversion percentage is to make sure the offense has a long way to go. And how do you do that? Don't let them get yards on 1st and 2nd either.
These are the best coaches in the game - and Foster is THE best - not because they are really good at stopping the other team on 3rd down but because they're good at stopping the other team on every down.
Except that doesn't answer why Nebraska is included (never higher than 35th in total defense, 26th in FEI, and 20th in S&P+) but teams like Stanford or Florida aren't despite having excellent defenses over the past 3 years. Scheme, tight coverage, and pass rush play into as well. Otherwise, it would be exactly identical.
Sure, I just mean that the driver behind the stats isn't anything magical about third-down specifically. One way to do well here but not overall would be to be good at everything else but give up too many explosive plays so teams will tend to not be able to move the ball much but when they do they cover huge yardage (so, Nebraska). It's only gaining one first down whether you're tackled just past the line or 50 yards downfield.
Similarly Florida and Stanford have been very good at preventing explosive plays and teams have just had trouble sustaining drives against them so they give up more third downs but remain very effective at allowing many points.
Yeah, I can agree with this. Leg for you!
Now offense MOVE THE FUCKING BALL. Seeing stats like this next to a 22-17 record make me upset.
*soothing voice* shhhh... shhhh.... it's ok... Teller's got this.
With Narduzzi now at Pitt, this means that our annual games with them are going to be defensive slugfests. I am quite okay with this.
Just gonna dust this ol' thing off.