Similar question. I’ve seen lots of moves that diverge from the ones they’re “likely” to do that were covered in the preferred openings. My question is not whether the openings are still good (I’m sure they are), but when to diverge versus doing what I often see in Nelson’s rating climb videos, just going for pawns in the center and standard development, or pouncing on what seems like an early weakness.

Second question. I’ve struggled with the Stonewall, but absolutely love the Colle, and yet they’re almost identical save for where that kingside knight goes (above or below the f pawn). For me the trouble with the Stonewall is knowing when to push e5 (versus leaving the stonewall structure in place), and actually getting the rook lift to work. Whenever I try it, it seems to get shut down, and then my rook is in an awkward spot. I don’t seem to have those troubles with the Colle, despite being so similar, because it’s natural to push e5 once you’re done developing, and just play on from there (even though the engine always wants you to play c4 instead of the Colle c3). So the question is what are the big advantages/disadvantages to the Stonewall vs. Colle?

I have the same question about recognizing when to “abandon” the standard opening moves when you notice the opponent make an unusual response in the early stages. As one type of example: they bring the queen out early so you would be inclined to chase it.