The two omissions that complicate Jellicoe's reputation

Why does Jellicoe lose ground in some rankings of British admirals despite his performance at Jutland?

The failure to force ammunition reform and to solve Beatty's reporting problem reduced the chance of an earlier, more decisive engagement.

Two criticisms shape this assessment: Jellicoe did not press shell reform when he had the authority to do so, and he did not overcome the information failures coming from the Battle Cruiser Fleet. Accurate reporting from Beatty could have brought the Grand Fleet into contact hours earlier. A third daylight engagement would have made German disengagement much harder and increased losses among already damaged ships. Jellicoe did not handle the battle badly, but earlier institutional and command decisions limited the result.