Yeah, in 2010...

But this is 2016, and now Serperior is very popular not only on Battlespot, but on battle simulators like Showdown as well. It's in Smogon's OU (overused) tier now: http://www.smogon.com/dex/xy/pokemon/serperior/

Wondering why it's so popular now? Hint: it only involves a single move in its learnset, not some expansive movepool...

Good thing you're allowed 5 other Pokemon in your team

And it's movepool as a whole is still jank. It's thanks to an OP hidden ability that it found better usage.

Going off topic but if what you say about it is true then I'm actually surprised such a one dimensional Pokemon is doing so well. I struggle to even bring mine into the match with every team having like 3-4 Pokes that resist it. 

Yeah, it's movepool as a whole is trash. But my point is that an expansive learnset isn't the be all, end all. If a Pokemon has other redeeming factors, then usually one or two moves are all it needs. I've faced plenty of Contrary Serperiors both online and in the Maison: the one consistency between all of them is that the opponent doesn't give a damn about type matchups and resistances. He/she/it is going to spam Leaf Storm and get that special attack sky high no matter what you throw at it.

Hell, I just faced a guy with one two nights ago; I had a Delphox, a Mega Pinsir and a Dragalge on my team: three Pokemon that resist grass (two double-resist) and can one-shot it with the right set up. The dude didn't care: he kept spamming Leaf Storm and Giga Drain like there was no tomorrow, and I barely won the match. If you allow that thing to freely get off two Leaf Storms and can't outspeed it, you just might be f'ed.

But getting back to the point, from a competitive, PvP standpoint, there really aren't as many Pokemon that benefit from a huge movepool as you think. It's nice to have, but it's usually not the deciding factor on whether a Pokemon is good or not. Again, Donphan: has a godly physical moveset variety, but most people don't use it as a straight up attacker. Hawlucha and Blaziken have an OK moveset variety, but most people only use their two STABs plus an attack-boosting move (I've seen a lot of people with only one on Blaziken too).

You originally said having an expansive movepool is better than being dual typed, which can be true, but my point is simply that dual typing makes it more likely for a Pokemon to have a good movepool. Whether or not a Pokemon is competitively viable is a different discussion, one I generally don't involve myself with. :L

Yeah pretty much any Pokemon will screw you if you allow it, but because Serperior is so 1 dimensional you always know exactly what it's gonna do thus it's far easier to counter, plus it's mono Grass lel. You still won the match so there you go! I only play double battles so maybe it's better in stealth rock battles, but I've never had too much trouble against it. Here's a fun example I was bored enough to bother uploading!

View on YouTube

"You originally said having an expansive movepool is better than being dual typed..."

I never once said that, and it's never been the point that I've been trying to make. Having an expansive movepool is not automatically better than being dual-typed, or vice versa. You have to look at each Pokemon on an individual basis and figure how its stats, movesets, typing and ability come together.

And I will say this again: having two types does not automatically mean a Pokemon is more likely to have a good movepool. It's all up to what GameFreak wants to give it. I could sit here and name dozens of examples, but if Pokemon existed in real life, you could pick up a rock and throw it, and you'd be likely to hit one that proves my point.

So you forgot your initial post already. "A diverse and expansive movepool is better than having two types."

Hence it's "more likely" rather than automatic or guaranteed. A dual type not having moves associated to one of it's types is a rare occurrence. We don't know exactly how Gamefreak decides what's what, but it seems they usually give moves based on appearance and of course typing.

Yeah, I forgot, my bad. I've been so back and forth in so many forums the past few days that I get my conversations mixed up. I still don't think that having two types automatically makes a Pokemon better. Like I said, it's just one factor among many. Mega Aggron actually got much better once it went to monotype.

Once again, that was never what I was getting at, my last post made that pretty clear.

"Dual typing simply ensures you have moves from atleast two different types."

We've both made our points clear a while back, but since we're being anal about syntax now, I guess I'll just say that outside of a few Pokemon that are purposely gimmicky like Unown, what Pokemon doesn't have moves from at least two different types? If that's your whole point, then that's an easy platform to stand on...