Board coverage refers to how well a player’s range of hands connects to the all possible flops, turns, and rivers.
For example, if you raise with a range containing only high pairs and high-card hands (AA, AK, KT, QJ, etc.), your range has bad board coverage because most of your hands will miss on low and medium flops (such as 8-7-6 or 6-4-2).
On the other hand, if you raise with a range containing the hands above plus suited connectors and low pairs (55, 7♥ 6♥, A♠ 2♠, etc.), your range has better board coverage because at least some of your hands will hit every type of flop.
