In that case then, it's pretty much a judgement call. I'm not lining up against the prior bar's H/L or using any other prior price relationships as an entry point. In a down trend (for instance) I'll be looking for the pullback up to be slowing down and have already turned back down. A couple of bars down with clear momentum restored to the underlying short-term trend and I’m sold, quite literally.
As mentioned in the post to which you refer, I’m also basing my ‘expectations’ of potential reversal back to the underlying trend on more than one technical SR level providing the necessary brake on the reversal at a specific level so it’s not just the price action, it’s the ‘understanding’ others will also be doing exactly what I’m doing for the same reasons which provides the self-fulfilling ‘credibility’ of these levels, but I’ll also do so with an eye to the institutions who trade large and who have customer order flow in front of them as well as research data that is likely somewhat superior to mine, (just possibly) knowing that I (and 100,000s of others) probably will be doing what we think we’re about to do, which is why I don’t react on the bar of the ‘apparent’ reversal to the underlying, but only with the follow through.
That said, you can get an idea I don’t pull anywhere near 100% of the run, and tops and bottoms are things I save for my spare time, but I do get an awful lot of successful middle thirds or thereabouts. The amount of any given slope I’ve taken on each trade doesn’t look much at the end of the day when I see what piece I had out of each move, but then I look at the W:L and the P&L and I normally feel a little better about that.