[10intheCrunch]

We use a fresh battery in every single match, no exceptions, and test on fresh batteries at the lab, so thats not a problem.

Second, the only serious wear problem we've had has been tread (we use waffle tread, it goes quickly), but surprisingly, it made no difference. The program we took from our lab, with our creaky, worn practice bot with almost no tread left worked perfectly on our smooth practice bot with new tread.

I maintain that sensors will only complicate the process, though if you do not have a practice robot and no way to test and calibrate dead reckoning, it can be difficult. A sensor program could conceivably be written and used with no testing...