There was no battle of Yavin IV. Seeing they had just blown up the pride of the Imperial fleet and killed millions of Imperial servicemen, the Rebels found it wisest to evacuate the moon before the Imperials could counterattack. And looking at the strength of the retaliation when it materialized (an armada of Imperator Class ships led by the Executor herself), I cannot disagree with their reasoning.
Sure, poorly researched games love to re-create a 'Battle of Yavin', but according to the movies and EA, it never took place.
"One of the bitches actually gave birth while she was attacking, and her puppies joined in on the carnage."
--the awesomeness that is Boatmurdered.