Like open raising 4xBB in HU SNGs

[SunOfBeach]

i can't see what a 4BB raise accomplishes that isn't accomplished just as well as a 2.5BB raise... except putting more money in the pot with marginal hands (if you're open-raising there as much as you should be).

[tewall]

This is obvious, but if the opponent folds too often to the continuation bet, then raising 4BB will gain more than raising 2.5 to 3BB.