The abbreviation GTO stands for Game Theory Optimal and refers to the best poker strategy you can take in any given situation to prevent your opponents from exploiting you.
In reality, it’s impossible to actually play GTO poker all the time since it is extremely complex, but it can be an invaluable tool when studying to understand fundamentally sound strategy.
Unlike many other poker strategies, this one doesn’t focus on exploiting other players. Instead, it aims to make it impossible for others to exploit you by always playing a balanced range.
For example, if you are considering whether you should open KTo from the HJ position in a 100bb cash game, the GTO poker strategy suggests that you should do that half of the time. This means that to play a perfectly balanced range, sometimes you need to raise, and sometimes you need to fold this hand.
The GTO strategy often involves different actions with mixed frequencies in the same hand, making it quite hard to actually implement it, especially in post-flop situations. Learn more about GTO poker strategy.