Shove or fold

Once stacks are short, raising and then folding stops being possible.

At that point, reducing the choice to all-in or fold is simply worth more.

From here you learn, hand by hand, the depth below which it is a shove.

• push/fold

  Play so shallow that the only sensible choices are all-in or fold. A middling raise would commit you anyway.

• effective stack

  The smaller of the two stacks involved. That is the most either player can actually lose, so it is the number that matters.

• BB

  Big blind. Because blinds keep rising in a tournament, stacks are counted in big blinds rather than chips.

20 hands or more, with an optimal rate of 70% and average EV loss no worse than 0.10BB