short term trading - week starting 16th sept, page-72

lapollonio,

It is unusual (but not impossible) for a bull flag to retrace this far ... in my experience it is the bull flags that retrace in the upper half of the spike (down to 50% retracement level) that have a better probability of success.

Also Probability of success is a function of the market in which it occurs..

Bear market... Bull flags usually lack penetration power when the top of the flag is broken.

Bull market ...High prob that Flag break will result in a new short term high.

All the above is in General and is IMHO.