I understand that hydroboration followed by oxidation is used when we need to perform hydration of a double bond against markovnikov’s rule, however, at what point is the markovnikov’s rule broken? According to markovnikov, the halogen of the hydrogen halide attaches to the carbon of alkene bearing the fewer number of hydrogen and greater number of carbons, so does this mean the rule is broken when the conditions are changed as to where it attaches? (That was the original rule formulation of Markovnikov’s himself. Now, we understand the rule broader: instead of halogen, it can be any negative part of the reagent. The rule usually works if addition proceeds through a carbocation, which is not the case for hydroboration. - GS).