Since there are four wheels, that's 10,000 possible combinations. So a straight brute force try all the combinations in sequence would be tedious. It turns out this lock employs false gates on all four wheels, spaced every other number. It's easy to feel these gates, but not so easy to distinguish between false gates and the true gate on each wheel. I've viewed some videos where others do supply their methods for discriminating between the false gates and the true gate; I guess my hands are not that trained.
However, half the numbers on each wheel can be excluded since they represent no gate. That changes the possible combinations from 10x10x10x10 = 10,000 to 5x5x5x5 = 625, a significant reduction in trials required to decode a given lock. This to me seems to be a design flaw in the lock.
