>>43331703Another thing I want to add is that HP is calculated differently than other stats.
Pic related, for example, is a Mew with no investment in any stat.
And here's the HP vs defense calculations for Mew:
>252 Atk Abomasnow Wood Hammer vs. 252 HP / 0 Def Mew: 154-183 (38.1 - 45.2%) -- guaranteed 3HKO>252 Atk Abomasnow Wood Hammer vs. 0 HP / 252 Def Mew: 123-145 (36 - 42.5%) -- guaranteed 3HKODespite Mew having a 100 in both HP and Defense, investing into defense means it takes a slightly lower percentage.
The difference is slight, but it shows that you should probably run the numbers yourself to see which is better for the specific threats you want to survive.