Would I be right in saying that a "maximum drawdown" is the biggest drop from the highest point of the bank?

Ie if your bank grows from 100 to 25,000 then goes down to 12,000, is the maximum drawdown $13,000?

Also, do you express it as a %? (In this case, 52% of bank was lost from maximum down to 12,000).

If this is all true, then over an extended period, what's the maximum drawdown you want to be able to endure? For example, the system I am currently testing in another thread has, over a 2 year period, a 58% maximum drawdown. This is over 6000 bets, using 1% of bank as the bet size.

Would this be considered "acceptable"?