Polly calculated the bio-index scores for a potential 2012 showdown between Obama and General David Petraeus. According to the bio-index, Petraeus would have a fair chance of winning the 2012 election: he achieved an index score equal to Obama's.

However, since the bio-index model incorporated an advantage for the incumbent in the case of a tie between the candidates, the model would still predict Obama to win 50.5% of the popular vote. That said, General Petraeus would certainly be within striking distance. In fact, he is the second strongest potential Republican candidate based on the bio-index - after Texas Governor Rick Perry.

But thus far, neither Perry nor Petraeus are part of the race. Petraeus actually ruled out to run.

The table below shows the codings for the two candidates Obama and Petraeus. If you spot any mistakes in the coding, please let us know.