I use my left hand for B, right hand for H, both for Y (most likely left hand if it's a capital Y, right hand if it's a small y since I never use the left shift). Sometimes I might use right hand for B if I'm typing something like "base", or left hand for H if I'm typing something like "HP".
Also, I thought I was using both thumbs for space bar, but apparently it's just my right thumb. The left thumb is just laying on top of the space bar doing nothing.