Part one of this topic was posted more than ten years ago. Put simply, the hydride nucleophile attacks the carbonyl from an axial rather than equation direction with a ratio of 10:1 (ΔΔG 1.37 kcal/mol). So does the model I previously proposed10.59350/aqrgh-jw887[.cite] support this and give any indication of why the stereochemistry is axial?