Largely played as in it has or had a good following in the past, so no obscure games that not many people know about. Also, not any banned characters or prepatch whatevers. Preferably the most recent iteration of the series, but I guess there could be previous games just for the sake of it.
For that game meaning that they are hard to deal with in that specific game regarding the mechanics or whatever. e.g. XvSF Storm would beat ST Rog pretty badly, but that doesn’t mean Rog is less top than Storm.