My son was inconsistent too. Fyi he has ADHD and a language processing disorder. He's never played competitively, but he was kind of obsessed with it when he was six. He was sometime spot on (he'd beat me and his older sister) and other times he was totally on the moon and couldn't win to save his life.
A third variation is sometimes he'd take a dive to prematurely end a game if he thought he couldn't win. Then he'd want to start a new game, and sure enough, if he got too far behind, he'd place himself in checkmate to end the game. It was very obvious (I even called him on it and he owned up to it). The whole thing felt very perfectionism related.
Anyway he was six, so at that age inconsistency is par for the course with most things. Plus he was playing purely out of interest whereas Gabalyn your son has a more mature objective (ie competition, skill building, self-improvement, etc)
You mentioned this: "I do think it is the retrieval/automaticity/procedural learning deficit." ...this rings true to me. With my son's language processing issue and his ADHD, part of his challenge in many things is generalized application of a previously learned skill. He too is now ten, and behaviorally and emotionally is much more stable but still has this automated retrieval issue sometimes. So... it's relating to the LD and not the age.
They say that LD never goes away, but arrrgh... I hate that!!! There must be something we can do... like exercising a weak muscle. I think the concept of neuro plasticity conflicts with the "LD is for life" idea. So which is right? Plasticity!!
I like your perspective of it being a life lesson. Sometimes they need to overcome a challenge so they learn that challenge is ok.
