Originally Posted by
gerv
Still seems like a bunch of unnecessary work. I've never had to do this before and I've adjusted lots of rear derailleurs. When you move your chain into a cog and it's not lined up correctly, you'll know pretty quickly. Same for high/low adjustment. If you have adjusted the limiter screws too far, the chain wants to pop off the cassette.
I've haven't had to do it before either, it just took some of the trial and error out of the process. Normally I'd start with the chain on one of the center cogs and attempt to center the chain between the nearby cogs. Then I'd run through the other gears loosening or tightening the cable as necessary to get clean shifts.
Without the chain it's like lining up two pointers. Next time you have your chain off, take a look and see what I mean. It's probably more helpful when you're dealing with more sprockets and less margin of error.