Virginia Tech Defensive Efficiency in 2008

FSUncensored over at Tomahawk Nation has turned me on to efficiency stats in football, particularly those done by Brian Fremeau and by Bill Connelly from Football Outsiders and Rock M Nation.

Connelly's numbers particularly intreague me because they deal with how a team performed against expectations. For instance, the Hokies gave up 278 yards on the ground against Georgia Tech last year in Blacksburg. However, the Jackets averaged 5.8 yards per carry (without sacks) and ran the ball 49 times in the game.

Therefore, the Jackets SHOULD have rushed for 282 yards in that game. The Hokies actually did better at stopping the Jackets' run game than it seems on the stat sheet.

In the same game, Georgia Tech had 109 passing yards. But the Jackets only threw nine passes and averaged 8.1 yards per attempt in 2008, meaning they should have only thrown for 73 yards in the game.

By looking at the efficiency stats for the Hokie defense, you can see how the Hokies excelled at defending the run and struggled against the pass in 2008. It also shows how much sacks helped them stiffle opposing offenses.

All of the following stats are for ACC games only. Sacks have been taken out of the rushing stats. Numbers are rounded. The lower the number on efficiency, the better the defense did against expectations.

Abbreviations: YPC - yards per carry; Rush - opponent carries minus sacks; ExYds - expected yards for the opponent; Yards - opponent yards with sacks taken out; Eff - VT efficiency.

That's with the sacks taken out. When you put the sacks back in (for both the opponent and the Hokie D), Tech's efficiency drops to 0.908, which is pretty good. The Hokies were right about even against the ACC against the run last year, but the sacks make a big difference.

The same can't be said against the pass, however.

Abbreviations: YPA - opponent's yards per attempt; Pass - opponents pass attempts; ExYds - expected yards for the opponent; Yards - opponent yards; Eff - VT efficiency.

Ouch. The Hokies held their opponent to under their expected yards three times. One of them was a mere 0.2 yards under expected and the others were the only two teams in the league that didn't qualify for bowls.

Finally, we'll look at Virginia Tech's overall efficiency both in terms of yardage and points. The better way to look at point efficiency is by points per play rather than points per game. I've taken it one step further and adjusted them for non-offensive touchdowns.

Abbreviations: YPP - opponent yards per play; Plays - opponent plays; ExYds - expected yards for the opponents; Yards - opponent yards; Eff - VT efficiency; PPP - opponent points per play adjusted for non-offensive points; Plays - opponent plays; ExPts - expected points for the opponent; Points - opponent points minus non-offensive points; Eff - VT efficiency.

The Florida State game was the only game the Hokies gave up more than a touchdown of what they should have. It was also one of Tech's better games in yardage efficiency, showing just how costly the big plays by Florida State's receivers and Virginia Tech's turnovers were.