amateurs never play main lines

Main lines are variations that have develop over decades, a dance that many memorise and few understand. As a rule beginners know only the first steps of their respective dance and don't really bother focusing on their opponents moves, thus, when left to their own devices they lack the experience and memory to follow the main line and must therefore rely on their intuition and calculation.

That said you shouldn't dissmiss theese kind of moves so easily, sometimes many non-mainlines are yet to be proven wrong.

but other moves can leave a player who focuses only on main lines having to navigate their way through the early opening wasting precious middle-game and end-game minutes.

Because main lines are not "in".

By the time anyone plays them, the others forgot what the moves are. You are suppose to play passive moves in the opening!

I had the same problem dude,don't let it bother you,just keep playing sound,logical Chess and you'll soon crack them,most of the time,I know it's infuriating when they keep moving pawns and you're trying to develop soundly,castle etc. but that will fill their positions full of holes and if you know anything about Chess strategy,that's a great square for horses xD. Also they'll be severely set back on development.  

You see unlike in other games,justice takes place over our beloved board,and if you decide,you're going to "do it your way" and ignore the general guidelines and principles that we've all studied so hard,well most of us ,you will fall at some point.  Don't worry about it,most of them don't know what they are doing any way so as I said just keep developing soundly and playing strategically and eventually the tactics will show up (in your favor) and it's gg,shall we start again,this time I'll be black! ;-) 

So in short,don't worry about "main lines" that's only for strong players,most patzers don't play those and that's why you're told not to study them,instead focus on tactics which you WILL be able to use against weaker players (and even some strong players),I hear u though on the frustrating part though,you really can't stop them,I mean a move is a move no matter how sh**y it is lol

first thing you should do is remove that attitude. not all secondary moves lead to refutations or even advantages.

sometimes, playing non-main lines moves is actually a strength, not a weakness, and not just because of psychology or preference. there is a reason the most analyzed main lines can reach 30+ moves. most players below expert should not even bother trying to learn these long lines with plenty of side variations, and rather focus on playing in such a way that you get comfortable middle game positions with mutual chances.  most players are missing so much in their learning, that not knowing 20+ moves of theory is NOT the main reason you are at that level.

even experts and weaker masters play "junk moves" all the time, and win vs stronger masters. think of such moves as very slight inaccuracies, and whether they are punishable (or even worth trying to punish) to be choices you have to make. its when you start thinking of moves like "junk" that you are likely gonna get a rude awakening. 

Agreed,it's better to understand then to memorize and ironically understanding a line will not only help you memorize it but it will also help you to play solid lines when one deviates from "book moves".   Perhaps one should view the book moves as a way to understand what's going on in the position along with the general principles,instead of just trying to thoughtlessly memorize a long line of moves and think that'll do it.  

The truth is most beginners deviate from these book moves because they don't know any better,or maybe they don't know the whole line and so they play something you don't know how to respond to it and there you go.  I know it's frustrating as I said,but if you understand the position,you can deviate from the "main line" and play something sound.  

I call myself a student of Chess and I believe that really good Chess players have a very deep understanding of the game which obviously aids them,something I'm seeking after,at my own pace that is........haha cut me a break,street fighter is fun and so .............hahaha yeah well! 

When someone doesn't play a mainline, is that a problem with the person or with the mainline?  A big part of knowing the mainline is knowing WHY it is the mainline.  That is, why is it better (or thought to be better) than the alternatives?  If you know this, you should have a pretty clear idea of what to do next.  If you don't know this, then you don't really know the mainline, you merely know the moves.

As a side note, I find it amusing how many amateurs say, "I didn't know what to do / I messed up because I don't know the theory," and yet we also say, "Nobody plays mainline theory at amateur level."

I just had a look at the second game briefly,haha that's what you're concerned about,you know how many players I play that play "h6" or "a6" or just push pawns in general when they should be developing their pieces.  That's when you have to throw the main line away and use general Chess principles.  ALL opening theory in Chess,whether it be the French,Ruy Lopez and you name it, they are all based on one golden rule and that rule simply is to DEVELOP YOUR PIECES!,......so having a look at that game there armed with the knowledge of the "Golden rule",you should have no problem knowing what to play next.  

You could easily play 4. Nf3 and have a lead in development and depending on your level of understanding with Chess,you'd know that you'd be winning the game right off the bat as Black simply should not dawdle with moves like h6. 

Then why do you call it junk?

If all you do is memorize the main lines, then you are absolutely right, you can't refute their junk because you are absolutely clueless on what the heck you are doing and when your opponent deviates, you are completely lost because you don't know what you were doing in the first place, you simply memorized moves.

Give you a perfect case in point.  I am a French guru!  I understand the French Defense better than any other opening in all of chess.  I have won many beautiful games in the French, both as Black and as White, and often times against much higher rated opposition.

At the same time, I can just as easily regurgitate the Seville Variation of the Grunfeld - 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Bc4 c5 8.Ne2 O-O O-O Nc6 10.Be3 Bg4 11.f3 Na5 12.Bxf7+.  Great, I spewed out moves through White's 12th.  I don't understand it.  The Grunfeld is not my cup of tea, and I make no claim to understand it.

If I tried to play the Grunfeld as Black, and White deviated, I'd be just as lost as you are.  Hence why I play the King's Indian and not the Grunfeld.  I understand the King's Indian, not just memorize it.

The following article shows 2 garbage lines against the French Defense, and if you don't understand the French, you'd be completely lost in these two games, but I explain in the article thoroughly why what White played is bad when he deviated from the norm.  Having a true understanding of an opening rather memorizing a bunch of lines is critical.  Even my results show.  In the 2717 tournament games I've played thus far over the board in my lifetime, my winning percentage with EITHER COLOR in the French Defense is substantially higher than my winning percentage in the Grunfeld with EITHER COLOR because I understand one and not the other!  If you want to succeed, you need to understand more than just the main lines!

http://charlottechesscenter.blogspot.com/2018/06/the-french-connection-volume-9.html

He calls it "junk" I think because the move, A) Deviates from the main-line,which he probably knows or has memorized and B ) the move doesn't add anything to the position,if you see my earlier comment about Black just playing h6,I tend to agree,that is a rubbish move,but as I told him,he should be happy about that and any Chess player with a bit of opening knowledge probably would play something like Nf3 in a flash,aka develop your pieces in the opening.  

Unless I'm missing something,I can only surmise that's why he called the move rubbish/junk.   I didn't notice the "refute" thing until now,first of all that's nonsense because there is nothing to refute here,as I said simply go about developing your pieces and you will soon have a tremendous lead in development which could lead to and easy win if Black isn't careful!. 

a lot of people would have considered Kramniks Rg8 against Aronian in the candidates a junk move, but  if a super gm does it its ok so remember the trick is to be a super-gm!!!

How about a super-hero?

I can tell you why I do, but I'm not a beginner.  I don't play main lines because I don't know the main lines, lol.  I know the names of the openings and what the moves are for those openings, but beyond move 4 or 5, I'm completely trying to figure out what to do.

If chess was just playing main lines, no one would bother playing. It'd be too boring.

Sidelines aren't even bad most of the time, and they lead to interesting and complicated positions... if you find that frustrating I honestly wonder how much you even like chess.

If a mod did say that, then my opinion of mods just got even lower.

The reason that i ask these questions is to get constructive answers，not trash talk like this。I know you‘’re just trying to get arise from me， so ihave decided to ignore that comment instead.