Which chansey is better at 1000 cp? 15Sta/10Atk/15Def, or 15/15/15?

I'm pretty sure the one with less attack performs better
+ 999 CP is boss

the maximum annoyance is a nothing. it gets beat like a drum with 20-30 seconds to spare. you may think it's annoying but it is not.

The lower atk IV Chansey would be a better defender if you want one below 1000cp. I would go for 1300+ CP Chansey given the resources though, it still stays motivated for an obnoxiously long time and wastes significantly more time when battling at full motivation.

theoretically the +15 attack one as that has more chance of causing a knockout or switch, which is more time consuming than the few seconds having more hp/def would gain (and the 1/2 a level higher at same cp won't make up for that).

practically who cares. gyms amirite ?