How important are ivs for Blissey?
Chanseys are extremely rare where I am, in the event i got like 2, all other candies have been from walking my Blissey (over 500km now) or hatching Chanseys.
I evolved my first Chansey 89iv and got Pound Psychic :'(. Walked a ton more, and then hatched a 96iv Chansey! evolved it and got Zen Headbutt Psychic :'(. So now what should I do? I have a level 20 84iv Chansey and level 2 91iv Chansey I can evolve after I walk a bunch more with my crap Blissey. Or should I settle for my 96iv Blissey? The 96iv one will sit high in gyms but is garbage with its moveset and we also have the gym rework coming and who knows what thatll do to the importance of ivs and cp placement. What would you do, evolve another chansey? or power up my garbage 96iv blissey?
Also, why is Pokebattler.com showing Zen Headbutt Psychic the second best moveset for a Defending Blissey against Machamp!?
Answers
A decent leveled attacker (Level 28+) will not care your Blissey has ZH/DG. If they have a decent roster, they will clean it out whether you have the best moves or the worst. They just see a simply near 800HP mon where they have to waste more time (and potions/revive) on and will either move on or tear your gym down.
I think it's unwise to keep trying to evolve Chanseys when all you should care about are IVs and gym placement (still 6th on the max CP scale) so power up and put her in a gym and fuggitaboutit....
I don't agree with the common wisdom that Blissey with the worst moveset is better than the next best pokemon with the best moveset (ZH/BS Snorlax, IMO). However, your 96% IV ZH/P does not have the worst moveset, and it's not garbage at all. I'd love to have that pokemon, and I'd max it as a priority over anything else in my pokedex. I would actually consider that to be the 2nd-best moveset, or maybe 3rd, because ZH constantly chews away at fighting types, and psychic (also SE against fighting types) is considerably harder to dodge than hyper beam.
Don't let the Gamepress letter grades deceive you; you've got a very elite defender there.
If I were you, I'd pick whichever Blissey has the highest attack IV, or whichever one has the highest CP potential. Chansey are also incredibly rare for me, and although I was lucky enough to get a few during the Valentines event, it was nowhere near as much as others. I did have one stroke of luck, and caught a wild level 30 Chansey. It only had 71% IV, but it had a perfect attack IV of 15.
My options were: Evolve the level 30 and be able to power it up to my max, or evolve one of my better IV level 20s and not be able to power it up all the way.
I chose to evolve the 71% IV Chansey, and was lucky enough to get ZH/DG, but the real kicker is that at level 34.5, it is at CP 2905 out of a possible 2966, which is just under 98% of Blissey's maximum CP potential. Like others have said, one of the biggest issues with fighting Blissey is that it's a time sink and resource drain, and will deter players who don't have the time to handle that. This problem will be compounded if your Blissey is higher up in the gym. Either the attacker has time for a few minutes of battling and shaves off some defenders below you, or they plan to take down the entire gym and are forced to strategize to decrease the number of times they have to fight your Blissey.
So, I'd say go for whatever gets you the highest CP. Attackers won't know what moveset your Blissey has until they fight it, and forcing them to deal with a Blissey higher up in the gym will act as a deterrent for lower level players or those with time constraints.
