Note that it's good to be angry about losing or doing poorly. The trick is to really feel the pain, and not take the easy route out and find excuses in the things that weren't in your control. High feedback situations or 1v1 games give you fewer opportunities to dip out of the internal locus of control mindset.
Maybe. I'm with you on the [not seeking excuses; embrace feedback] parts, but not "good to be angry". Unsure about "control mindset"... care to expound?