For me:
defensive openings: (damage reducer and high power, cards like
Yookie,
Ottavia,
Burt etc)
for example:
otavia 2-3 pilz
you will not use this type of openings if your opp has card like vickie or
Kolos because they can deal heavy damage even if you reducetheir damage
or your opp has pillz manipulator, because if they win, they will get back their pillz
advantage:
this type of opening has lower risk
to create pillz advantage (if your opp use pillz)
or win the battle because your opp don't use sufficient pillz
disadvantage:
you cannot use this opening if your opp has many good cards
wall opening:
using card like
Zatman to make your opp scare and don't use pillz or trying to pile up pillz to win against him
for example: use 1-3 pillz on
Zatman:
advantage:
many people don't want to deal with this monster and let him pass through
if your opp try to out pillz him, you still get pillz advantage
disadvantage:
experience player know about this and hit
Zatman with their best card (with small amount of pillz)
many times people will reduce his damage, so don't expect he can always deal 4 damage
attacking with wall:
for example:
Zatman 4-6 pillz
this type is to deal with opp that has many good cards
advantage:
if your opp trying to hit with their best card (maybe they will do this because they think
Zatman is a bluff) your opp will suffer heavy loss
disadvantage
if they don't use their best card, you are the one in disadvantage now