Rushing bomb-site "B" on CS:GO's Dust 2 map is a popular but extremely poor tactic frequently used noobs and
professionals alike when funds are running low on
the Terrorist side. Bomb-site "B", which is far more confined than bomb-site "A", is
theoretically easier to take with cheaper weapons that lack accuracy at long range. Sadly, most attempts to "rush B", especially when the Counter-Terrorists are expecting it, end in a massacre for the Terrorist side.
The term "rush b" is often shouted over voice chat, especially by Russian players, who tend to use this tactic more than American or European players for some reason.