Just wondering: I know this might sound stupid but is it possible to apply a clause that doesn't allow to make baton pass work when the user has boosted stats? That would solve the problem without banning anything (even if it is actually a sort of ban).
Despite this question, I personally feel that we can't generalize the bpass issue across generations. The point is different in Adv than ORAS/BW as example while DPP looks like in a middle way.
Unlike the OP said, I wanna see the issue from a point of view regarding a likely BP + boost because I believe this is the best solution to get rid of the issue as Tennisace said. A lot of people would disagree but, as also McMeghan said, every other different way to solve this problem seemd not working enough, and this was ok since BP issue only regarded non-tournaments games for the majority of cases because even if BP strategies always looked awfully cheap, people didn't use them in tours for several reasons like matchup issues (this applies mainly for 3-4 gen where magic bounce wasn't a thing), fear of the hax (the only safe way to beat this strategy together with that horrible and uncommon move which is Haze) and mostly sense of "sport" because, as you can see reading comments of almost every battle involving BP, user who runs BP strat was usually considered as a dick.
Things changed (see McM references), and so it should change also the way to deal with this problem.
I state that I won't focus on full BP chains because they can all be settled down with BP clause (we might allow 2 users instead of just 1 for what regards gen 3 -and maybe 4-, while in gen 2 I would like to keep things as they currently are)
So, I would like to start with ADV while it feels like the "common sense of playerbase" don't see BP itself as an issue but just in really few cases:
- the evil drum pass (smeargle)
- perish trap pass (umbreon + lax/cune + Magne to trap skarm and deal with other common phazers as zap/cune/swamp)
Adv phazers are quite common since they are one of the most used ways to deal with ddancers like mence/tar (swamp/skarm) or cm stuff (zapdos/suicune) so bpass seems not that evil (just raikou could be a threat but dugtrio destroys its dreams). A BP + boost ban here should compromise other solid and stable sets like Celebi's, which is one of the most used and effective mon of the tier (this is really important), definitely not broken (annoying tho) and with a lot of ways to play around it.
In shorts: every team of every playstyle shouldn't have issues with BP because the metagame's general perspective allows to play around it without giving an entire slot (or just a single move) "just to deal with bpass".
The problem here is definitely not BP but smeargle drumpassing (and also umbreon trap passing but w/e) so a complex ban would be acceptable.
DPP:
Huge differences with Adv. Now scarf users can revengekill statup mons so offensive teams don't need necessarily a phazer and also some kind of balances don't have to "force" one in them. Number of mons is raised so teambuilding issue inevitably raised, despite a good number of bans which appeased the "power creep" issue. In all of this, BP issue finds more difficulties to have a full slot dedicated for, but generically phazers are quite common (skarmory swamp hippo etc). Note that some kind of teams really find hard to deal with BP now so the matchup discrepancy became more a thing.
what are the mainly BP issues? Full BP and Gliscor/Celebi pass.
forgetting about full BP, we can see the main difference between the above-mentioned mons in just one move, as someone already said: TAUNT.
I don't really know if there's the case to do a blanket BP + boost ban here or just BP + taunt (is Gliscor still an issue even without taunt?) or a Gliscor+BP (can Gligar do the same job? Can every other subpar choice be as effective as Gliscor is? Do they worth the slot as Gliscor does?). Surely Celebi statpasser is not one of the main mons of this metagame as it was in Adv so a likely BP + boost ban won't drastically ruin the staple metagame even there is not the need to cut off all its use just because Gliscor is an issue.
in shorts: Gliscor pass is more an issue than Celebi's, and every other passer seems not working as well as it, so it seems that fixing the solely gliscorpass stuff would be better.
BW:
this gen is way far too much different from previous. Power creep extremely increased and now it's definitely more difficult to deal even with certain single mons or playstyles (how many team can't deal with all weather/dragons/reuniclus/Volcarona/BP/gengar/tailwind off/TR off/etc all together? Not even considering differences in weather(less) HO/bulkoff/balance/semistall/fullstall)
There is not enough space for every playstyle to deal with BP even tho slow-roll strats like full BP or screens + BP need too much turns to work so phazers or good offensive priority users (ES Nite) could work. Sometimes they can't do nothing at all anyway, just think about magic bounce users or faster pass strats like Smashpass or also Quiverpass.
Unlike previous gens, the issue here seems to actually be BP itself because once you get rid of smashpass there will be quiverpass or just tg+twind/trickroom pass or other kind of bs well supported by screen, memento and speed control moves) and for this reason I believe we can think about a BP + boost ban here. "Wait but Celebipass.." chill dudes because in BW there are already too much things to think about it and I think that sole statpass absence can be seen as a "one less problem" in the tide of things we have to think about when teambuilding.
in shorts: some new features, added to power creep increase, made BP an as niche as dangerous playstyle that you can't deal with in most of cases without losing anything else more useful for more used stuff that could let you lose. Also the sole statpass became a niche playstyle that can be """sacrificed""" in order to avoid an useless whirlpool of bans like "first smashpass then quiver then that other etc" while the sensitive problem is not what baton pass but the batonpassing itself, so we can think about a BP + boost blanket ban.
ORAS
basically the same as BW, with even more features to make BP dangerous (Scolipede and geomancy e.g.) and many more mons (including megas) to make matchup issue even more terrible: not coincidentally, the people awakening on the BP issue started here. BP became so dangerous that it just needed ONE single passer to make stored-espeon still viable, other than all these sort of quickpasses. I strongly support a blanket BP + boost ban here because even stuff like Celebipass on certain threats can be terrifying for several kinds of teams which could lose to something else more diffused just to put stuff to not lose to BP. We have to consider also that BP strategy became stronger and with many more ways to prevent usual ways of threatening (like phazing etc).
in shorts: oras is a "worse" bw for what concerns BP issues so I support a blanket BP + boost ban.
The whole issue should be solved asap foe tours' sake