Quote from logic_man:
Once you have a number of trades, executed on whatever basis, aren't you using statistics when you pick and choose among your future trade opportunities?
In other words, is it any different to say "I see a pattern that has a 55% chance of reaching a certain target price" than it is to say "There is a 55% chance that the spread on these two items in a pair will reach X before it reaches Y"?
Ultimately, there is no "sure thing" in trading and once you leave the realm of "sure things", you inevitably enter the realm of probability and statistics.