How is max hp calculated in pvp?

Max mp at least seems to matter, changing max mp changed the number of times I could use a skill in the waiting area until my mp completely emptied.

PvP HP works different then PvE HP.

Sometimes when I end PvP and lag a bit, I can see the HP itself go down really fast just before returning to the PvP town, meaning I have less HP in PvP then in PvE, I don't know what the ratio is though.

Also, if you switch damage for HP equips, your score will go down, since you do less damage, it's not much (like 10%~20% less) but it's present.

That happens just to heal you, it goes down going both ways then fully heals you.