How can someone that hasn't developed the ability do exceptionally well? Am I missing something?
You are not, IMO, missing something. They are challenging papers which would require ability. However, how is that ability developed? In the maths section many of the questions are 'word problems'. At my DDs' primary they would not have been familiar with these in any way. However, their prep schooled friends were practising questions like this from an early age. It didn't make them better at maths, but the preparation did allow them to develop the ability to answer these questions and then put them at an advantage, given all else (ability) being equal. So, I wonder, are St Paul's factoring into the equation that some children will have been prepped for the exam throughout school, some will be tutored and some will be reliant on nothing other than their innate ability? I applaud the sentiment but question the efficacy of its application. As nobody implied, hooray if we ever get an exam that tests ability/aptitude not previous education. I am not holding my breath.