The diamond in the Method R Corporation logo is the kind of diamond that you see in flowcharts.
It represents the key distinction of the method itself: that there is a deterministic decision-making process that leads you—and everyone else, regardless of their experience level—from a single starting point to exactly the aspect of performance in your system that you should be focused on next. Method R is the antithesis of trial-and-error tuning, and we chose the diamond for our logo to help remind people of that.