As in many technical disciplines it is necessary to consider more than one possibility and then choose the scenario that you believe is the best fit.
The result may often be wrong however this does allow the trader to pick a threshold on where he/she believes they are wrong and allows for an exit point to reduce the loss in the case of an incorrect assessment. Learning to accept where you are wrong is one of the most important skills to learn as a trader.
As a fellow trader friend of mine once said; I would rather not be in a trade, then stuck in a bad one.
With both the EUR/USD and GBP/USD at important levels vis-a-vis the potential Elliott Wave Counts, I am presenting alternate possibilities in the even of breakouts.
Cheers
'Market and Human' Psychology perspectives with tips on how to avoid common mistakes by 

