I haven't watched Marty's vid yet. I usually refer folks to Lionel's Youtube vid. I find Mike easy to follow and slightly entertaining as well. There is a graphic explaination of what happens when they aren't phased.
MattR posted:Because I'm simple........ what is the benefit of phasing?
How about not feeding your track twice the voltage you expect for starters?
I learned to do this over the phone with Gramps as an elementry school kid,
Not hard, and very necessary if 2+ transformers share any common circuit.
Not a bad saftey precaution if they don't actually share a circuit either.