A dretch with strafing movements in its approach is, all things considered, much easier to avoid getting hit by. In fact, if a human sprints backwards from a dretch that has too much sideways movement, the human will outrun the dretch. Getting kills with dretch is not about simply not getting shot. The most important thing is the speed with which you get to your target. Trying not to get shot while you do it is an obvious must. However, if you move extremely randomly, it doesn't matter how many shots you avoid, you WILL have terrible general results. You can't just wallwalk and short jump randomly and expect to get a kill.
Maybe we could use some demos of good dretching, I think it could be pretty beneficial.