Masahiro Sakurai spoke to DenFamiNicoGamer (via Siliconera) during an interview where he discussed the development of Super Smash Bros. Ultimate and his role within the game. Sakurai was responsible for the creation of the game's new fighters, but as for the actual balancing of the massive roster of characters, he said he wasn't directly involved.
"Well, it's not just that," Sakurai said when the interviewer suggested that most of the time spent on the game was probably tense balancing characters. “Actually, for Ultimate the system was changed so that I don't directly work with the character parameters myself.”
Sakurai explained that he'd helmed the balance adjustments in the first Super Smash Bros. , but he later created a team for Super Smash Bros. Brawl and every game after it was tasked with monitoring battle data and making adjustments accordingly.
“From Brawl and onwards, I made a monitoring team to collect battle results, and used that data and proposed options to adjust character data, ”he said. “For Brawl the team was made of around 4 people, and they'd basically finish at 4-player battles, so there would be a bias towards that. There was also a team like that for Smash Bros. for 3DS / Wii U but it seems they are not enough. ”
Super Smash Bros. Ultimate however, was differently accounted for the scope of the game. Sakurai said they brought people who were "good at battling" before adding that the previous system had talented fighters as well, but this time it was more organized. The game director said he was looking for points to change and would make comments if any issues arose. He wasn't responsible for balancing the state of characters himself, but people would approach him with questions or comments as he oversaw the whole balancing process.
"Although I didn't balance the parameters myself, the staff would suggest things like , 'I want to make it this way,' and I'd end up watching over the entire process, 'Sakurai explained. “That said, even doing this, I still think that“ a game is fun if it's fair. ””
Sakurai was involved directly in the process of choosing new characters though with the game director explaining back in November that Nintendo would pick out DLC options and he'd then decide whether or not a fighter could possibly be created out of those choices.