Can I think of the Slav as a 'reverse' London, and the Semi-Slav as a 'reverse' Colle-Kowltanalski?

@DGerardP yes, that is indeed correct. And welcome to the world of anti-London hate. 

Hang on Thrillerfan. As you know I am new to chess, but I know that Carlsen had played the London quite a few times, and the Barry London. And what about Kamsky's success with the London. And Yusopov with the Colle-Z. (I don't know about the Trompowsky I'm afraid). Take care, Daniel

Thank you Mister Wind Up Bird. This thread has been very helpful for me. I've just one seven games in a row! Mainly playing the London as white. And, as black, just playing a sort of slav/London mash-up. Obviously I'm only in the low 900s and only started at age 48, 9 months ago, but these basic ideas, patterns, shapes, principles are really helpful for me. 😀 London/C-K/C-Z and their 'parings' really make sense at my level. But also clearly for many Grandmasters too!

Meant 'won'.

Notice I never mentioned the London as a "One Time" occurrence, but also note that NONE of the people you mention play the London exclusively.  All the names you mentioned have played it sparingly, and only when appropriate from an opening perspective as well.  For example, you won't find then playing it against the Modern Defense (1...g6).

I still must emphasize that way too many amateurs take a single or "select few" occurrences and think it's gospel, and validates them to play it all the time!  That is so far from the truth!

You will never find a 2700+ GM play any of those openings exclusively, or even as their "primary" weapon.

Lower rated players are too black and white.  Oh, such-and-such played it once and this other guy played it 5 times in his career, it must be a great opening!  There is a reason why GMs have made careers out of the King's Indian, Grunfeld, QGD, Slav, Nimzo-Indian, Semi-Slav, French, Sicilian, 1...e5, and the Caro-Kann, yet no World Champion or challenger has ever made a career out of the Alekhine (even Alekhine himself only played it a select few times), Modern, Scandinavian, Leningrad Dutch, Owen's Defense, or the Englund Gambit.  It's because they are weaker.  That doesn't mean a GM will "never" play them.  Anand played the Scandi in 1995.  But you will not find anyone that uses these, or the London, Colle, Torre, Trompowsky, etc, as their PRIMARY weapon!

Yeah, 2.Nf3 first gives black the option to play:

1.d4 d5 2.Nf3 Nf6 3.Bf4 c5 4.e3 Nc6 5.c3 Qb6 which most london players try to avoid. Virtually everyone nowadays gives 2.Bf4 primarily to avoid this line. White is still fine here by the way, Kamsky has entered it numerous times, but probably more comfortable equality for black since he has 6.Qb3 c4 7.Qc2 Bf5!

Playing 2.Bf4 allows white to avoid it by: 

1.d4 d5 2.Bf4 Nf6 3.e3 c5 4.c3 Nc6 5.Nd2

Or even possibly: 1.d4 d5 2.Bf4 c5 3.e4!?

Also, playing 2.Bf4 first is more flexible in sense that white can transpose into Jobava or even Pirc stuff if he wants. E.g. 1.d4 Nf6 2.Bf4 g6 3.Nc3! Which is probably stronger than traditional london vs. KID.

They are certainly inferior to the Queen's Gambit and Catalan. Because some GMs use them occasionally to surprise opponents doesn't mean anything.

I haven't really looked at KIA much, but all the other openings you mention just give black multiple ways to get immediate equality.

White is still getting a small edge from the Queens Gambit and Catalan, so they are all better attempts from white to play for an advantage out of the opening rather than London, Colle etc. which give white (at best) an equal position.

Of course none of this matters for human players, but objectively they are weaker options.

Good points Thrillerfan 😀

And thanks to you Thrillerfan - and to all the other contributers on this thread - as this thread has been very helpful for me!  😁

And now - all of you - can I please direct you to a post that I created 22 hours ago on General Chess Discussion called Weakening Castled King's Defences. So far it has had no replies! Can you guys help out a lowly 900 please and take a look at the question and let me know what you think..... Ooh, I'll post this then put that question here too. Thank you.

This is what I wrote friends. With all of your and other brilliant responses to other questions I've posted, 1000 is not far away! 

Okay, I'm pretty new to chess, bit love it. Been playing 9 months and ranked around 900 rapid. I'm pretty bad but getting slowly better. Of course it will depend on the situation and plans but can it be good sometimes to provoke weaknesses? For example, I love the London/Colle/Torre systems. If I move my DSBishop to g5 (when Black has Knight on f6) - like in the Torre - and if this is met by h6, I could slide my Bishop back to the London f4 position. So now black pawns are on f7, g7 and now h6. Are there now opportunities to exploit this? Thanks.

#27
Carlsen and Kramnik have played Colle and London repeatedly. It is not inferior to Queen's Gambit or Catalan. Chess is a draw. The white advantage is an illusion from the 20th century.

#19
Hold your horses.

If you do not believe me, then believe Fischer on the King's Indian Attack:
"I thought it led to a favourable variation of the King's Indian reversed, particularly after Black has committed himself with ...e6"

Did you seriously just classify the King's Indian (apparently the first example to spring to your mind as your fingers flew across the keyboard) as objectively much stronger than a London?

Really?

Have you by any chance been frozen in a glacier for the past quarter century?

If so, man are you in for some more surprises...

There is nothing wrong with the Colle-Koltanowski at 2400 ELO and below (let’s be serious… not many people get better than that) It’s not exactly playing a black defense (semi slave ) as white with a move! (As quoted above) and being passive. The lines the Colle-Koltanowski represent don’t really happen as Black. They are sub lines or off shoots.

The issue is… you have study the opening just like any other opening. One can’t play it as a system. If you are going to adopt it, you must know what to play when Black avoids it. (And avoid they will… One has to ask “why is that if the opening is what people say it is” ???

By the time you develop these responses, the different lines, the theory will be pretty extensive. The main plus.., is that your prep theory will be practical … (who has study a defense but rarely ever gets a chance to play it ?)

If your going to play the Colle Koltanowski you will need know Anti-Colle Bg4 or Bf5 lines (So far White retains and edge in these)

And a serious line against the Grunfeld set up (pawns at d5 & c5 with g6 & Bg7) … A Catalan Reversed with an early dxc, pawn to b4 and Bb2 is my go to. (I haven’t seen a computer that doesn’t give the resulting positions and edge for white)

And the King Indian defense … Koltanowski himself recommends white playing the main line KID g3 and Bg2 lines. (In Smith and Halls work on the Colle they recommended several responses and one of them is what I call the “French Bayonet attack …” it’s the French line in the KIA in reverse … myself I have had good results with that… totally takes the Sicilian Dragon/ KID player out of his comfort zone (at the club level)

The main line Colle-Koltanowski the position 10…h6 is still unclear as far as theory goes (still lot’s interesting ideas not yet played ) & has only been reached 7 or so times in professional play (as a club player… no one has come close to going down that line with me )

Also to play the Colle-Koltanowski you have to study endgames. Often my opponents attempting to thwart the usual aggressive intention the opening is known for… on the king they often go into a passive endgame. 

Finally I leave the reader with a quote from John Cox . From his book “Dealing with d4 deviations “ in the 1930s the top guys didn’t know whether these openings or the Quees Gambit were better. These were the 2700s of their day, they understood chess better than I do (his peak ELO was 2423) he goes on to say he could list a hundred 2550+ players who have succumbed to this opening (and other d4 deviations) and that they produce a red blooded struggle as any opening.