Originally Posted by lapka
I always thought, that GTO is a strategy against which the opponent can not increase his EV through changing of his strategy.
Now I encountered a different definition in micro LH forum
It said basically, that GTO is a balanced strategy, which maximize the EV.
Can somebody give a correct definition?
I'm not an expert, but I think your first definition is of an unexploitable strategy. A GTO strategy is a special type of unexploitable strategy; it's the unexploitable strategy which maximizes expectation against an opponent also playing unexploitably.
GTO strategies definitely do not maximize EV in normal circumstances, however, since no one plays GTO in the first place. We maximize EV by exploiting our villains, not by playing unexploitably.