Board Thread:Fun and Games/@comment-30736697-20170508230558/@comment-28362353-20170602135559

Actually SSB is stronger in both the manga and the anime. In the fight against Black in the manga, it is stated that SSB is far stronger than SSG, but SSG provides better Ki and Stamina control, so they use SSG to keep their stamina and ki in check, then right as they are about to attack, they switch to SSB to maximize the damage. Then Goku attains what people are calling "Completed SSB" and he has perfect ki and stamina control in it, making it his strongest form.