To put a gentle spin on Frank Spaziani's tenure at Boston College, it's fair to say that his success--such as it is--has been predicated on consistently strong defense. And this consistency goes back much further than that. If there's one thing you could count on from Boston College, post-Tom O'Brien, post-Jeff Jagodzinski, post-Matthias Kiwanuka, post-BJ Raji, post-Brian Toal etc etc, it was tough defense. The offense has been something of an adventure since Matt Ryan's departure, but the defense has been there throughout, weathering whatever turnover came its way.
That is, until this season. The offense is still anemic but producing at basically the same rate it did a year ago (they're averaging 18.4 PPG vs. 18.5 last year), when the team was good enough to reach bowl eligibility. But the defense has collapsed; opponents are averaging 1.3 more yards per play in 2011 than they did in 2010, which is a massive cliff dive. They're less effective at stopping the run than they have been in a long time, and the strains are evident all over the place.
(For some perspective, NC State's infamous 2009 defense also allowed 5.7 yards per play.)
The other issue is turnover margin. As is often the case for teams with iffy quarterback play, BC's offense is turnover prone. But at least in 2010 the defense forced 33 turnovers, good for the 7th highest total in the country. They finished +8 on the year, which is the sort of number that can push a mediocre team over the borderline into bowl eligibility. This season, the defense has forced just 10 turnovers in nine games, and the team has gone from +8 in 2010 to -8 in 2011. The offense has maintained a steady 2 turnover/game average through both years.
So 2011 has been a worst-case scenario in several ways. The bottom fell out on the defense's down-to-down performance, and they've been hit with bad luck to go with it. Now the Eagles are out of the bowl picture for the first time since 1998. In hindsight, they needed their offense to make a leap to compensate for some of the defensive dropoff, but that's a lot to ask of Chase Rettig sans Montel Harris. Maybe the well is finally running dry up in Chestnut Hill, but whatever the case may be, it's no surprise that this performance has led to these results.