A Common Hand Reading Mistake

This is certainly a weakness in my own game that I am currently addressing. Here's what happens: We get to the river and all of a sudden our opponent shows strength. Say the board is 4682J. We suddenly think, "oh no our AJ cannot be good he must have a suited one gapper for the straight". But actually, since the player is only playing 15% of hands preflop over a sample of a few hundred hands and has played his hand from under the gun we cannot reasonably include any low one gap hands in his range. We are acting on the river in a general sense without thinking about all the information we have. I was made aware of this mistake by poker pro/coach [vital]Myth from the cardrunners videos. He's a great coach and I highly recommend listening to what he has to say, you'll learn alot. Anyway, what this advice has led me to do is to create some rules of thumb for general play.
A player who plays less than 12% of hands will usually not have any suited connectors in his range. This is why good players often call in position against these "nits" since if we flop top pair on a 652 board, we'll have the best hand most of the time; or we can take the pot away if low cards flop.
A player who plays between 12% and 20% of hands will usually only be playing suited connectors without a gap in. So on the first board we can pretty safely rule out straights when making our decision.
A player playing more than 20% of hands can usually have any suited connector and many Ax suited hands so nothing can really be discounted. This is part of the reason why most of the top professionals play 25-30% of hands. It is hard for most opponents to figure out their hand.
edit: A player who plays over 30% of hands will actually have quite a large percentage of bluffs in their range and so we can safely start to call more lightly and give them less credit for having it, despite it being within their range.
Important Note
Unless the hand sample size is really large, these rules should only be used lightly. It may just be that someone has been dealt 73o 50 times in a row.