Opening Repertoirs are for beginners.

Yes, beginners and amateurs benefit from "opening repertoir", Top Gm's don't even pretend to have one, so please...

learn from databases...(edited just the colour)

To have an opening repertoire is mostly a decision of style. Some people build extremely broad repertoires but still avoid certain key lines. Some openings just appeal to some players way more than others.

A part of my repertoire as white is as such:

I play the move e4 but rarely anything else. If my opponent plays e4 e5 I will play the move Nf3, but never the king's gambit or the vienna game, for I do not believe they are sound. If my opponent plays Nf6 I will play the Nxe5 d6 Nf3 Nxe4 d3 Nf6 c4 lines.

Playing for a crucial dynamic difference in the pawn structures and threatening d4 critically after some preparation(Be2 and 0-0).

If my opponent instead plays Nc6 I usually play the Ruy Lopez, but have been booked up on the fried liver and Gioco Piano games in order to surprise my opponents if I really need to. If I hit Bc5 I play b4 and if I hit Nf6 I go Ng5. 

If I get to the Ruy Lopez then the real game begins:

Against the Berlin Wall I tend to play the New Age variation:

The Rook on e1 acts like a sledgehammer and if black dares to trade rooks there are problems.

Should black opt for a more classical setup with ...a6 I have a few tricks up my sleeve should my opponent be unprepared to deviate.

I tend to play the Zaitsev like a classical French.

When I play the Chigorin I almost play the classical plan of locking the center, but occasionally I'll play dxe5 and Qe2 and it gets interesting. It also is highly dependant on what my opponent plays.

I typically will play into the Marshall to show that I am not afraid, in addition to the fact that handling the a4 lines feel alien to me. 

Finally, against the Janowski I play right into the mainline, since once again, I am hardly afraid of it. 

And that's my repertoire against e4 e5.

1.c4 as white

Benko Gambit against 1.d4

1...d5 against 1.e4

Thats my entire opening

your right Top Gm's don't 'pretend' to have one.  they actually have one; a 'set' of opening moves that they are comfortable with.

so this thread starts off with a joke... is the idea of a beginner having a repertoire a 'joke' too?  some people with better memories might play similar moves in similar position (the very definition of a reportoire)- its not SUCH a bad move, if said beginner doesn't waste a lot of time on it.

this is no joke, is what I think: we should learn from databases.

Do you play only play for draws in the petrov? :p d3 wouldn't even be a candidate move for me there. Principally speaking a symmetrical position where it's white to move is still a minute advantage, but you can safely play far more ambitiously. Also in your Berlin, I would play Qe2 (instead of d4) making life difficult for the king and thinking, not b3, but putting my bishop on f4 eyeing the potentially weak c7 pawn, but not necessary.

I was going to say read Tal vs Botvinnick 1960.  Tal studied his own openings and all of Botvinnick's openings extensively prior to the match.  Reading Tal's notes, he talks about studying particular lines of particular openings that Botvinnick used in other matches on the off-chance they might pop up in his match.  And if I was going to play Nakamura (ha!  In my dreams!), I'd sure as heck be studying KID.

Databases are great and all, but I like books like Tal. It gives you a great look into the thinking behind the play.  Generally, databases give you a bare bones recital of what was played, not the why.

ETA: Here's a quote from Magnus Carlsen (emphasis added): "...But I don't know what talent consists of.  It's not true that I don't work on chess much.  I think about chess all the time, and before the match and during the match we spent a lot of time preparing different openings." - http://en.chessbase.com/post/carlsen-interview-after-the-match

Says the 1300 skrub

Why not both? I think "databasing" up on theory and statistics can help guide your play, even though you probably won't even notice a difference in your game, AND reading books helps. Speaking of which, Nimzowitsch's "My System" is a must have. In the end if your middlegame and endgame is poor, your openings are almost meaningless.

1300 with 4 games, 3 less than 9 moves...maybe I'll stay here who knows...

Databases are great, but if you dont understand why a move is made, the database isnt much help.  Using a database and not understanding "why" is like using a chess engine and saying "I'm .4 pawns better" but not having a clue as to why youre better.

agree, so that is the idea, this variation was abandoned because...now the best moves are x/y because...100%.

I don't agree... there is NO point to learn moves you don't understand.  and databases is full of moves that no beginner (and actually intermediate) will understand.

moreover, at the patzer level- you opponent will quickly get out of any book!  what do you intend to to about it? 

being unprepared (when they get out of the book) isn't an instructive answer... 

so see- I agree with the Single guy 100%.

and not stuzzi.  this is a wierd thread.   I'm just a patzer- but I have my opinions- YOU curl up to the MCO and strive to memorize line after line.

I don't see this as instructive.

... and we had this convo- a little while back "Chess openings are under-rated". I'm not a strong player- but some strong players VERY much said this.