The biggest challenge for cash game players looking to transition into tournaments is adapting to shallower stacks and the strategy changes that go along with it.

Cash game players rarely play under 100 big blinds (BBs) deep, and are used to ranges and strategies that reflect very deep stacked poker strategy. In poker tournaments, especially towards the endgame, the average stack is usually quite shallow.  

It is not uncommon to see a final table of a poker tournament with a number of 10BB stacks. The chip leader may only have 30 or 40 BB!

Tournament professionals have spent a lot of time and energy studying and solving these strategies for shallower stacks. A lot of these short stack ranges and strategies will be counter-intuitive to a cash game player, and take some time getting used to. However, these are the stages of the tournament where all the money is on the line so it pays to be prepared.