>>29146599You should never split defenses (Put less than full in both defences), unless you really know what you are doing, and are trying to hit specific survivability benchmarks. Don't put 80 in both, just put 160 in HP. With that said, point for point you do get slightly more bang for your point buck by investing in defense, provided that that point gets used.
If you are using a Pokemon with a draining move, absolutely prioritize defense. If a Pokemon will be passing Wishes, absolutely prioritize HP.
If you are putting stats on an attacker, I like to prioritize HP, since there is no telling what they might get hit by. If you have a dedicated tank, put the stats on the defence you expect them to use.
Some Pokemon, like Chansey, get so much out of full EV investment in their off defense that it is a crime not to. That said, don't run Bold Chansey. You only get a pittance of defense for that.
In general:
Bulky offence: Full HP (Conkeldur, ectetera)
Tank: Full on one defense
Wall: Full on HP and one Defence
Pain Split/Drain move user: No HP investment. Defenses only.
Wish Passer: Full HP
Chansey/Blissey: Full Defense and HP, Calm.
Assault Vest: Full Sp. Def. You get a buy two get one free deal, so use it.
In most cases, make sure your HP is odd. It may not seem like it matters, but you'd be surprised how much it comes up. If you are relying on something like Belly Drum+Sub to activate a Berry or something, stay even.
If you need to run a -defense nature because you are running a mixed sweeper, in general go with the lower stat, to minimize your losses. Do keep in mind that most priority is physical.
