Halsey made the cut to 5 star rank, but only barely. Ray Spruance was considered for that last 5 star navy promotion but was blocked by those that thought Halsey should get it.
Halsey lead his fleet into twp typhoons toward the end of the war. The Navy Board let him skate on the first one but President Truman was the one to make the decision on keeping him in command.
So the last 5 star rank came down to Halsey or Spruance. Spruance was the lessor known so he got passed over even though Nimitz thought he should have been promoted. His condolence prize was that when he retired, he retired at full pay and benefits for life.
Interesting side not is that Nimitz, Spruance, Adm's Richmond Turner and Charles Lockwood are all buried together in Golden State National Cemetery in California. They were all life long friends and wanted to be together after their deaths.
The rank was really created so that Ike as Supreme Allied Commander in Europe would not be Junior to A Brit Field Marshal. The letters of appointment are each one day different. The first award of 5 star promotion went to Admiral Leahy, Roosevelt’s personal military advisor. The next day General Marshall received his promotion, the next day, Admiral King, then General MacArthur, Admiral Nimitz, then Ike, and the final promotion to 5 star during the war to General Hap Arnold.