gambitfan: Below a message I have just posted at Queen's Gambit Declined Semi-Slav, Meran (D49) ; it is a comparison between the two lines...Hi everybody !
Let's have a look at COE (Chess Opening Explorer)...
With 136 141 games, 1 d4 is the second most common first move behind 1 e4 (193 024 games)...
If after playing 1 d4 you play on COE the statistically most common moves, you obtain following series :
1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. Nc3 c6 5. e3 Nbd7 6. Bd3 dxc4 7. Bxc4 b5 8. Bd3 a6 9. e4 c5 10. e5 cxd4 11. Nxb5...
This is the line above with a transposition of moves concerning the four first moves...
COE's database gives 226 games happening from 1925 until 2006...
Since I am (like Bobby Fischer) a 1.e4 player, I concentrate on Black winning games : there are 61 of them (27% of 226).
Among Black winning games with great players, there are :
Miles vs Kasparov, 1986
Van der Sterren vs Shirov, 1995
Kan vs Botvinnik, 1953
Lilienthal vs Botvinnik, 1941
The position of most common line apparently held by Queen's Gambit Declined Semi-Slav, Meran (D49) might in fact be challenged by one of the King's Indian lines...
After 1. d4 Nf6 2. c4 you have :
2... e6 (33 320 games)
2... g6 (21 228 games)
At the second move QGD "beats" the King's Infian but 2...e6 also leads to Queen's Indian, Nimzo Indian,... while 2...g6 is less "split"...
After 1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. Nc3 c6 5. e3 Nbd7 we obtain 4 220 games
After 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O (King's Indian most common line) we obtain 6 982 games, which makes KI more common than QGD after the 5th move...
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. O-O Nc6 8. d5 Ne7 9. Ne1 Nd7 10. Nd3 f5 11. Bd2 gives 262 games, which, after the 11th move for White, makes the King's Indian, Orthodox, Aronin-Taimanov (E99) more common than the Queen's Gambit Declined Semi-Slav, Meran (D49)
After 1. d4 Nf6 2. c4 e6 COE gives 3. Nf3 (18 768 games) as the most common 3rd move before 3. Nc3 (16 405 games)...
If 3. Nc3 is played, then 3... Bb4 (13 640 games) is by far more common and more aggressive (25.3% Black winning chances) than 3... d5 (6 044 games, 18.5% Black winning)
3. Nc3 clearly incitates Black to play the Nimzo Indian by far more aggressive... 3. Nc3 is a "sharpening" move...
3. Nf3 avoids the Nimzo-Indian ansd seems to "force" Black to answer 3... d5, which leads to a "quieter" game...
3. Nf3 is a "softening" move leading to a "stable" game...