I quoted the name of the thread as given. I'm too much of a chicken to create my own Russian examples. :P

All examples as given on that page which you posted are correct, but the parts you modified when you wrote your post are not. It mostly depends on the context, my examples gave some contexts in which one or the other deviation from the norm is possible. That's a good example for something you cannot put into rules conclusively. The rules give you the three main types of if-clauses which you can use, and some contexts allow for deviations; but you have to understand the way the formative rules and the context interact in order to get valid sentences.

After a couple of years or decades of noticing such things in English (or actually any language) as it is being spoken or written you reach a point where you become able to form correct if not rules-conforming sentences. It is much better to notice sentences which deviate from the norm and try to develop a feeling for the deviation and why it is used, than to look for a rule to explain it.