Scott wrote on 05/15/09 at 23:42:23:
[quote author=BPaulsen link=1242322828/0#5 date=1242424035
The ScottM2 structures are the most nuanced when arriving via 1.c4/1.Nf3, and require the most expertise.
Could you elaborate on that a little bit? In which ways is that so, and what do I need to be careful of? [/quote]
This is tough, move orders are very specific. I won't cover them all (way too many, I spent many, many hours over many years working out the fine details on all these variations), but I'll give a brief idea.
ie: Black has to decide between Hedgehog, and QIE.
(for example, sooooo many transpositions are possible, each requiring their own knowledge, so we'll go with one move order)
1. Nf3 Nf6 2. c4 b6 3. g3 Bb7 4. Bg2 e6 5. 0-0 Be7 6. Nc3
Black is already confronted with two distinct options that actually produce dramatically different demands, and confusing the two results in huge edges for white. Black needs to decide on 6...c5 (Hedgehog), or 6...0-0 (QIE).
The 7. Re1 Hedgehog isn't as dangerous as the 7. Re1 QIE. However, if one is a Hedgehog player then 7. d4 cxd4 8. Qxd4 is a huge mass of intertangled variations with super-specific move orders (one misstep by black will land him straight in a lost middlegame from about move 9-12) dictated by what white does. Hedgehog players must also be able to play the lines of the classical ...Bb7 QID, and be ready to transpose at any point.
The 7. Re1 QIE is more dangerous because black doesn't want to be 0-0 early in Hedgehog lines, so it rules out effective ...c5 systems, necessitating an early ...Ne4 (more effective if not 0-0, particularly against effective against the equivalent of 7. Re1 Hedgehog), or ...d5.
There's also move order issues arising from 1.c4 Nf6 2. Nc3, and now black has to deal with options like 2...b6 3. e4! Alternatively 2...e6 3.e4! suddenly forces you out of comfort zone if you play the black side of NID and QID variations. White even has 3. Nf3, and if you're not a NID/QGD player, then suddenly you're in no-man's land transposition-wise. It's the reason I respond to 1. c4 Nf6 2. Nc3 with e5! and 1. c4 Nf6 2. Nf3 (or interchange white's first two moves) with e6!
1. Nf3/ 2. c4 isn't dangerous because it objectively grants white large advantages. It's dangerous because white is in comfortable territory and gets to dictate exactly where the lines end up (different options often producing dramatically different positions), which can be bad for opponents not thoroughly prepared. About the only way to bail out and get to a relatively safe position with no effort is to play the KID, which isn't to everyone's tastes.