[LaPingvino]

playful engagement can also be useful or even important. I think open-mindedness is more important here: you need to be able to absorb new concepts and accept experience into your action during the practice. I think that's why people with autism (looking at it through the Intense World glasses) can learn some things really fast, although they don't intentionally train certain things.

[zemvpferreira]

Playful engagement is certainly important, especially if you're practicing skills outside of a structured, measurable, competitive activity, but I'd question anything being more important to mastery than deliberate practice: Is it my bias or are successful competitors almost always very serious during practice, and relaxed after winning "matches"?