I seemed to remember Cassel barely making the team last year after a horrible preseason so I thought I would go back and do some research. Brady was hurt almost all preseason so Matt got most of the starter reps.
Cassel "won" the job over Matt Gutierrez despite being outplayed, statistically speaking, the entire preseason. Cassel was only 19-of-34 passing and failed to throw a single touchdown pass in the teams four games. By comparison, Guitierrez completed 64% of his passes, threw a pair of touchdowns and put up an 85.6 passer rating (compared to Cassel's 56.6 rating).
Matching the reigning NFL MVP is asking too much, but Cassel has played better than his statistics in the first two exhibition games suggest.
In nine possessions, he completed 7 of 14 passes for 68 yards and one interception.
I don't know if he is just bad in the preseason or just really steps up his game when it really counts but I am hoping he gets it together soon.