Actually, a level playing field is NOT as you describe. It is one that provides supports for areas of weakness....for example, for the brilliant uncoordinated kid to be able to complete workusing a computer when their writing ability gets in the way of showing what they know...so that all kids can not only learn but show what they know.
All my older kids, and possibly my youngest as well though we are not certain of this, are well advanced beyond "average" yet public school in the elementary grades was a nightmare for them. That's why I homeschooled - there was so much emphasis on printing neatly that intellect was ignored, and this was to their detriment. They are all doing well now, but needed to have emphasis on thinking rather than neatness in the early years till their motor skills got within range of their ability to think.
Jane in MN