Likeliest team to go undefeated is ...

The Alabama offense has been very efficient so far this season. Scott Kane/Icon SMI

We've passed the midway point of the season and the BCS championship race is coming into focus. There are many potential scenarios that are still in play, and only a few teams can confidently claim that they control their own destiny.

If either Alabama or Florida wins the rest of its games, it will most certainly reach the title game. Upsets are inevitable down the stretch, of course, and that means it is too early for a handful of others to worry about their positions in the BCS standings. Kansas State, Oregon and Notre Dame may be jockeying for position now, but there's a pretty good chance that they, too, control their own fate. Take care of business and win the rest of their games, and they'll likely be there in the end. Trip up, and today's poll arguments won't matter much.

About a month ago, we ran an article detailing the statistical similarities between the top five teams in The Associated Press poll and national title contenders from recent seasons. We have a new top five to consider (only Alabama and Oregon are still in that group), and with more data collected, an even stronger methodology to calculate similarity scores.

We compared each of the top five teams in this week's BCS standings to every other FBS team over the past five seasons across 25 distinct statistical measures. Each metric was weighted according to its correlation with overall winning percentage.

Here is a look at the closest recent team comparison for each team in the BCS top five -- lined up by current BCS ranking -- including their chances of remaining undefeated the rest of the way and the remaining opponents that could provide the biggest challenges.

1. Alabama Crimson Tide

Most similar stat profile: 2008 USC (12-1 vs. FBS)
Likelihood of remaining undefeated in regular season: 42.9 percent

When we first researched similarity scores last month, the 2008 Trojans were the best fit for this year's Crimson Tide as well, and not much has changed for the reigning champs. Alabama's overall drive efficiency profile on both sides of the ball is very strong. The Crimson Tide rank No. 3 nationally in avoiding three-and-outs on offense (16.9 percent of drives) and No. 1 on defense (50.0 percent of opponent drives). The elite combination of offensive and defensive dominance carried USC to comfortable victories throughout the 2008 season.