Beat The ... Grünfeld

IN this series I am looking at the statistically best way to play against popular opening lines.

The numbers are drawn from the 2021 edition of ChessBase's Mega database, ignoring, where possible, those results that include very few games and so are statistically insignificant.

The Grünfeld: 1.d4 Nf6 2.c4 g6 3.Nc3 d5 is popular at all levels of chess.

White's most-popular responses are 4.cxd5, which scores 53%, and 4.Nf3, which scores 54%.

But of moves appearing more than 1,000 times in Mega21, the most successful is 4.Qb3!?, which scores 56%.

Position after 4.Qb3

Only two Black replies appear more than nine times in Mega21.

A) 4...dxc4 (919 games)

After 5.Qxc4 the line splits.

A1 5...Bg7 6.e4 0-0 7.Be2, after which the line splits again.

A1.1 7...a6 8.Be3 b5 9.Qb3 scores 75% for White

A1.2 7...Nc6 8.Nf3, when A1.2a 8...Bg4 9.d5 Na5 10.Qb4 Bxf3 11.Bxf3 c6 scores 57% for White with both 12.0-0 and the much-less popular 12.Be3, A1.2b 8...e5!? 8.dxe5!? scores 55% for White and A1.2c 8...Nd7 9.Be3 (this and 9.d5 score equally well for White but Be3 is much preferred by the analysis engines Stockfish13 and Komodo12.1.1) Nb6 10.Qd3 scores 63% for White.

A2 5...Be6 6.Qa4+ scores 59% for White, albeit from quite a small sample.

B) 4...c6 (110 games)

After 5.Nf3 the line splits.

B1 5...Bg7 6.Bf4!?, after which the line splits again.

B1.1 6...0-0 7.e3, when B1.1a 7...Qa5 8.h3 Nbd7 9.Be2 scores 93% for White, albeit from a small sample, B1.1b 7...e6 8.h3 Nbd7 9.Be2 scores 96% for White, albeit from quite a small sample and B1.1c 7...dxc4 8.Bxc4 when 8...b5 9.Bd3 scores 68% for White, albeit from quite a small sample, while 8...Nbd7 9.h3 scores 71% for White, albeit from a small sample.

B1.2 6...dxc4 7.Qxc4, when B1.2a 7...0-0 8.e4 b5 9.Qb3 scores 54% for White and B1.2b 7...Be6 8.Qa4 scores 75% for White, albeit from a small sample.

B2 5...dxc4 6.Qxc4 Bg7 7.e4 0-0 8.h3 b5 9.Qb3 scores 58% for White, albeit from a small sample.