Why Arceus-Dark ran Serious Nature 16% of the time in Nat Dex AG??

Question

In December, 2020 Arceus-Dark runs 16% of the time Serious Nature in its spreads. However, it doesn't carry any mixed sets. So what's the reason of this? And more surprisingly, all of Serious Nature suddenly disappeared in January 2021. Is it more of a glitch or anything?

Source December 2020's usage stats.

Now in January 2021, the latest usage stats say that most of the sets have Calm Nature. What caused the significant change in nature usage? Plus, this is for the highest ladder available, >1700. Which means that it's less unlikely for weird sets, so is it a error in Smogon's usage stats or anything else?

Comments

You'll probably get a better answer if you ask here: https://www.smogon.com/forums/threads/national-dex-ag-mega-thread.3672423/ It is possible that it was a mistake. A few years ago, Swinub got 4% usage in AAA.

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It's possible that one person laddered enough with a mistake on their team for it to appear in those stats. The sample size of people >1760 Elo running Arceus-Dark would be reasonably small.

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@sumwun Okay, I'm going to ask there. I was dumb and unsure where to ask, lol. @Fizz I had disagreed. Yveltal and it are the best Calyrex-S counters, however since Yveltal is the prominent Dynamaxer people use Arceus-Dark as Calyrex-S counter. It is the #15 most used Pokemon too. which might be a bit less.

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That comment is not to say Arceus-Dark isn't used often -- it's just to say that if you take the small group of people with 1760+ Elo and then reduce it to only people using a particular Pokemon, then there aren't many people left.

Answer 1

You never asked on Smogon, so I did it for you.

Serious:200/0/0/0/104/204
No idea but uh, Nat Dex AG ladder is full of people who don't know a lot of common strategies tbh. 38% of Cal-S and 31% of Mega Ray being Focus Sash and <1% of Nec-DM being HDB should sum that up.
Marshadow
| Items
| Focus Sash 86.059%
Yep, Ladder Rule 1 still applies.
Someone correct me if this is an actual spread plz, and tell me why it isn't Calm?

source

Comments

Umm it doesn't explain why did the Serious usage suddenly disappeared to Calm in January and February.

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Why don't you try asking that on Smogon?

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Okay then I will ask there.