It just came out good. nothing I did besides catch a 1,000 Dittos. Its IVs are far better than my ditto though. Poliwag is female Careful nature, the IV's 31 24 28 27 26 30. Attack is 24 but all the moves are special.
I used to have one(mach punch Hitomantop) a long time ago. he was good and I knew nothing of IVs then. I was building a team to go against battle tower. I fought against an awesome Mach punch Hitomantop in battle tower so I looked at Serebii.net and found out it was an egg move.