In-depth look at the 49ers' offense

49ers personnel report

This file breaks down the 49ers' offense every which way, with reports focusing on Week 15 and the season as a whole. A play-by-play sheet lets users sort all 2009 plays by multiple criteria.

Mike Singletary is genuine and I think that's one of the main reasons players respond well to him. They know he's not trying to fool anyone.

That genuineness is one of the things I appreciate about his news conferences. Singletary isn't always expansive on sensitive subjects, but he seems honest. His latest session -- the 49ers have the video here -- begins with detailed assessments for each of the team's three interceptions during its 27-13 defeat at Philadelphia in Week 15.

Tight end Vernon Davis was primarily responsible for the first one. The Eagles tricked quarterback Alex Smith on the second one, using tactics the Titans also employed. Smith made a poor decision on the third one.

More broadly, Singletary said the 49ers came into the game wanting to run the ball quite a bit, but the plan changed when they fell behind, 20-3. The explanation makes sense, but the 49ers' personnel choices early in the game baffled me some. The 49ers went two-plus quarters before running one snap from the Frank Gore-friendly base offense featuring fullback Moran Norris, two receivers and one tight end.

The 49ers did not turn to their base offense in a meaningful way until after Smith's 12-yard scoring pass to Josh Morgan closed the deficit to 20-13. Gore immediately busted a 37-yard run, followed by a 6-yard run, from this grouping. Smith failed to complete a pass in his only three attempts from base personnel, but it's not like he was consistently effective from any of the other groups, either.

49ers through the air: Week 15

The chart shows how the 49ers' passing game fared by personnel group during a 27-13 loss to Philadelphia. The team has had success this season striking downfield from its "22" personnel group featuring two backs and two tight ends, but the team did not attempt a pass from this personnel Sunday.

49ers personnel overview: Week 15

The 49ers averaged more yards per rush than pass attempt against the Eagles, the second week in a row that was the case for San Francisco.