Where naval promotion becomes strategic and political

At what point does promotion most often carry a naval officer beyond tactical competence?

The biggest break is usually between rear admiral and vice admiral, where strategy and politics become much more important.

Many competent captains can become capable commodores or rear admirals because the work still resembles commanding a larger group of ships. Vice-admiral responsibilities add far more strategy and politics. The rear-to-vice-admiral step is therefore where otherwise successful officers can become badly mismatched. Cochrane and Pye are examples worth examining, although naming failures properly requires a full explanation of the circumstances.