What IVs/EVs spread should have a pokemon (in particular Dragalge) to minimize the Life Orb recoil?
It depends in the set you want to run, but if you want to focus on minimized Life Orb Damage, you'd want to give it a spread of IVs and EVs that makes it have a total amount of HP that ends with the number 9. So if you had for example 159 HP, you'd have the maximum amount of HP, while taking 15 damage as recoil per attack. If you're running EV investment in HP, you don't have to worry about giving it a specific spread of IVs other than perfect (31) in HP. But if the Pokemon you're using has an HP stat that ends with 0 or 1 at an IV of 31 and 0 EVs, and it doesn't run investment in HP, you could give it a lower HP IV, that makes the total amount of HP end in 9 (which is usually 27 or 29, but it depends on the level you're using it at and what the total usually is at an HP IV of 31 and 0 EVs).
With Dragalge in particular, it pretty much always run HP Investment, so the IV spread 31/X/31/31/31/31 could work (unless you want a specific Hidden Power type). For the EV spread:
If you're using it at level 50, you could give it either 228 EVs in HP to get 169 HP, 148 EVs in HP to get 159 HP or 68 EVs in HP to get 149 HP.
If you're using it at level 100, you could give it 232 EVs in HP to get 329 HP, 192 EVs in HP to get 319 HP, 152 EVs in HP to get 309 HP, 112 EVs in HP to get 299 HP, 72 EVs in HP to get 289 HP or 32 EVs in HP to get 279 HP.
(If you have an HP IV of 30, you'd have to add 4 EVs to each of the suggested spreads, to get the right total of HP)
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