It could be something as simple as a lack of focus on table and seat selection. When I played cash games, I began to wonder after a while, why I always seemed to have the nits on my right and the LAGs, fish and maniacs on my left. And then one day it dawned on me, that this was because, someone else did not want that seat, and this is why, it became vacant.
Other than that the main difficulty when transitioning from tournaments to cash games is the fact, that there is much more turn and river play with 100BB stacks. So you have situations like getting raised on the turn with the threat of another big river barrel, which just does not come up very often in tournaments.
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