is memorizing 20 moves deep with ideas against an opening while being 1200elo is a bad idea?

you already know the question

If you have ambition to become a GM, it's not a bad idea.
If you only want to become casual player, it's a bad idea.

It is a bad idea in any case.

On average,....
.....
Against other 1200's you'll go 5 or 6 moves before they leave theory.
Against 2000's you go 10 or 11 (then they'll make a reasonable move not in theory). So 20 moves of theory wont help you play better compared to spending the time learning a few basic endings or how to play IQP positions or ...

Bill

It's not a bad idea, it's a good idea. However, at the lower levels, your opponents may not know the theory. You need to be able to win when they deviate from your lines and that comes down to your fundamental chess ability rather than memory.

Depends on the goal. If you like to learn and you enjoy the process of memorizing line then go for it, it can't hurt.

If you're just doing it to be a better player, there are more efficient ways imo, 20 moves is really deep but it's not the worst way either. It will make you an expert at that one opening so there's that.

Chess is learned backwards, from endgames to openings.

1200 ELO does not magically bring along with it the ABILITY to understand ideas in any opening. You have to work that out first, ideas which are a result of the kinds of middlegames the opening breeds.

1200's notoriously dislike endgame study for all the wrong reasons. Endgames teach you the 'physics' of each piece on a sparse board. It's the phase of the game you learn the most from. Philidor's Position is just that - you know it and you know how to execute it. Pretending you know opening/middlegame ideas is a massive potpourri of strategic themes you probably haver never seen before, let along play well. you speak like that is 'just an offshoot' of opening study and memorization.

Good luck.

As an intermediate player, it's a wasteful idea - in general for openings it's best to go wide rather than narrow.

The reasons for this are (1) your opponents are highly likely to go off-book well before the 20-moves are up and (2) there are plenty of 'off-line' moves which are perfectly solid if not popular or considered optimum.

By going WIDE you're less likely to be caught off-side by your opponent's pet - if not quite optimum/popular - lines. As such in the sub-GM level game familiarity trumps move-recall, by a long long way.

Lastly, the increasing scale of possibilities with each move is far greater than most non-professionals are capable of absorbing.

Well, my counter is, it increases Opening knowledge and punish more easily if they make inaccuracies

@AlexiHarvey said ^

As an intermediate player, it's a wasteful idea - in general for openings it's best to go wide rather than narrow.

The reasons for this are (1) your opponents are highly likely to go off-book well before the 20-moves are up and (2) there are plenty of 'off-line' moves which are perfectly solid if not popular or considered optimum.

By going WIDE you're less likely to be caught off-side by your op...

100% agree with this.

That said if you really want to go deep on an opening, just do it, why not? Studying openings is fun.

Still better to learn 10 variations 10 moves deep than 1 line 20 moves deep tho.