I remember Tom Williams being a big fan in his VSA videos giving...

I remember Tom Williams being a big fan in his VSA videos giving anecdotes about his old 5' ruler to draw oblique lines across large charts.
But a little confused over Dayton's position who seemed to use them a lot in certain videos, especially over short term moves but then dismissing their use in others....
Weis uses them a lot in his book and daily update reports.