FBO: Fantasy matchups Week 5

As the Dallas pace statistics regress to the mean, look for their RBs to gain fantasy value. Bob Levey/Getty Images

Trying to figure out why some of the players on your fantasy team are underachieving, even while it seems as if they're playing well? The problem might be one factor that rarely gets play in fantasy football analysis but is all the rage in statistical analysis of basketball: possessions.

Because basketball teams have so many possessions in a game -- and teams with disparate styles can produce significantly different possession totals -- researchers have developed tempo-free statistics that produce more accurate measures of performance and efficiency. A team that scores 100 points on 90 possessions is undoubtedly a better offense than one that scores 100 points in 105 possessions.

In football, the swing in possession totals from team to team is not as large. Our drive stats at Football Outsiders strip out meaningless end-of-half drives to measure performance on a per-drive basis; they suggest that the average team will have a little more than 11 possessions per game. In 2009, the Kansas City Chiefs had exactly 200 possessions, for an average of 12.5 drives per game; on the flip side, their AFC West rivals in San Diego had just 161 possessions, or just 10.1 drives per game. Naturally, those stats are influenced by the nature of those teams -- the Chiefs had one of the league's worst defenses, which gave them more opportunities to receive the ball on kickoffs, while the Chargers played against teams that typically tried to keep their dominant passing attack off the field by eating up clock. San Diego's mediocre defense often failed to turn those drives into three-and-outs, preventing the offense from getting back on the field.

While a swing of 39 possessions in a season seems pretty high, the differences can be even more drastic in a small sample. And with just four (or three) games on the books for the league's teams, some offenses haven't had a fair chance to show what they can do yet. As those figures regress toward the mean, the increase in possessions could mean that the players on those teams are undervalued.

So which teams should you be looking out for? Let's go with the three teams in the NFL that average fewer than 10 possessions per game: