In terms of finding the right push range, different tournament situations can have different complexity.
What could we do to understand, should we push that hand or fold it?
You have to upload the situation in ICMIZER, then assign expected ranges to your opponents, then click the button "Calculate" and find out the answer.
The problem is that the exact prediction of the call range for one of the opponents is impossible. In this prediction, we usually rely on three things: our experience, the view of Nash equilibrium ranges, and good luck.
In the context of this article we call complex those situations where the role of luck in predicting is significantly higher than in typical tournament situations.
To learn more, read the article "Analysis of difficult push fold SNG tournament spots".