I'm kind of amazed at how good Bisharp got it this gen. It didn't actually change in any way, but its moves, typing and the environment around it all changed as if to perfectly suit it. Now it has a more powerful and reliable dark type STAB with Knock Off, no longer needing to rely on Night Slash for reliable Dark-type damage. Both it's types got buffed offensively; Dark no longer being resisted by Steel is huge, and Fairies take Iron Head from being a grudging concession to being an asset. Defensively it didn't suffer from either the Steel or Dark type's defensive nerfs (lost resistances and new weakness respectively) because its dual typing covers all those up. Hell, because Flying type has become such an important offensive type now and Fighting types have become less common, you could say it's been indirectly buffed defensively. And all of this isn't even considering the biggest boon of all it got this generation; the Defog buff. Because of that, Defiant went from a small bonus to being Bisharp's defining asset, and cemented it as the very best Pokemon in an all new niche; Defog deterring.
Now I haven't used Bisharp, but I have played against it a lot and I think it's interesting to analyse the impact it has on the OU metagame this generation. I'd have to say the bit that makes it most interesting and powerful is it's ability to deter hazard removal simply by being on the field. You don't even need to activate Bisharp's Defiant boost to make it useful. Hell, it doesn't even have to hit the field. All it has to do it sit there and threaten, keeping your hazards safe and forcing the opponent to act in ways that you control. Bisharp basically becomes a spinblocker for Defog... one that doesn't even need to be sent out to do it's job. Add in it's natural offensive presence even without a Defiant Boost and you have a Pokemon that basically defines the word "pressure". One wrong move against it and you're finished. Its constant threat forces your opponent to play conservatively, something which any competitive player knows is a great help in controlling a match.
Now seeing as I don't use it, I'm more interested in ways to counteract Bisharp's assets than I am in exploiting them myself. The thing that really needs to be countered for Bisharp isn't preventing it from sweeping and breaking your walls though; it's figuring out how remove hazards safely when it's looming there as a threat. The most common counterplay for Bisharp that you see is taking advantage of the more predictable aspects of its play and hitting it when it switches in on a predicted defog, rather than defogging blindly. Of course, this is a prediction game and leads to some pretty heavy mind games, and the advantage still goes to the Bisharp user, especially since they can run stuff like Assault vest to allow them to beat you anyway. They have less to loose and can afford to make more mistakes than the person trying to get off the defog. Of course, the other possibility is to simply pass up Defog altogether and use a Rapid Spinner, but that usually means making compromises in other areas of your team composition, since if you can't fit Excadrill onto your team nicely you're going to end up having to use a less than ideal Pokemon like Starmie or Donphan. Another counterplay option is setting up your team so that it can handle a +2 Bisharp if need be, though this is hard to do with most teams. A new strategy I've been experimenting with are lure strategies; equipping your defogger so that it can lure in and eliminate Bisharp on it's own. This usually means compromising the defogger in other areas of its performance though, so I think it's only a real option if guaranteed hazard removal is an absolute must for your team.
I'm curious to hear if people have other ideas of how to play against Bisharp, not just ideas on how to better use it. Bisharp is one of those Pokemon that has to be considered during teambuilding because it fills such an important niche, so it bears talking about ways to deal with it.
