Yes, this is a discretionary approach, however the properties of a winning trade and losing trade change as market conditions change, and markets sometimes change in unprecented ways. What consistuted "winning behavior" before will not be the same as what it is now. As long as you are flexible and stay on top of things, then you might do well. But if you are rigid, then no.

Basic price behavior remains the same, but whether it is exaggerated or numbed changes as the market changes, and this is what you have to be on the lookout for. A breakout will always be a breakout, but it's magnitude and duration will be different each time a breakout happens and those parameters cannot be known beforehand.

A retracement will always be a retracement, but the point at which it begins and its length will not be constant.