I breathe after every 4 strokes. I did try to make it 3 but I can apparently only breathe on one side.
I think you might be able to swim faster than me.
I think I have to breathe every 2nd stroke...problem is when inhaling coincides with someone else's wash!
I found breathing every 4 made me more puffed, which made it seem like more of a workout. Definitely can't breathe to the left...