Usually the fields fetch API functions similarly to loading field values from doc values. Usually. It differs in a few cases like text. But whenever it does differ from doc_values we want to make that choice intentionally. So it turns out that when you use the fields API on a half_float field we'll parse the value from the _source as a 32 bit float and return it with that precision. But docvalue_fields for half_float returns 16 bit of precision. Do we really want that or did we do it by accident?