interesting. i am starting to see the value of BB %B. i use BB overlaid usually and go by candle/PA patterns at the extreme. don't you find that not having the mid Bollinger line leads you to mistime contra-trend (ie you enter the trade on a spike beyond the band in the opposite direction of the move that generated the spike) trade exits when price touches it or closes beyond it slightly only to resume the previous trend even higher/lower?
@isomorph, I tend to ignore the centre line focus more on the two outer lines as these represent the Bollinger bands. / Mirror image. So what looks like divergence isn't in relation to Bollinger bands. BB% doesn't measure spikes only the close.