Flank Opening (Grob's Attack)

Grob's Attack is generally considered to be one of the worst starting moves, and is possibly the single worst starting move, for White. However, if White knows enough theory and Black is caught by surprise, this opening can be playable even at relatively high levels. An unprepared player with Black can be led into dangerous territory, especially if they fixate on attempting to win the g4-pawn early.

It is named after Swiss IM Henry Grob (1904-1971) who analysed it in great depth and played hundreds of correspondence games with it.^[1]

With decent play from Black and slight inaccuracies by White, Black can establish a relatively large or even decisive advantage. White’s move significantly compromises their kingside's pawn structure, and places the g-pawn on an unusual square that is difficult to defend without giving Black the initiative and compromising the kingside further, as well as making kingside castling severely disadvantageous. Some players argue that, as compensation, White influences more kingside space and can fianchetto the kingside bishop, contributing to influence across the board, as well as discouraging ... Nf6 due to g5 kick. The general plan and idea is similar to the Polish Opening mirrored horizontally. But, kingside space is usually completely ignored since f5, g5, and h5 are rarely played by Black, and Black may just develop the kingside knight to e7, avoiding the kick threat. Also, Black can occupy and take control of the centre, and continually threaten the pawn, gaining initiative.

Play tends to vary between the Grob Gambit 1. ... d5 2. h3, e3, g5, or c4

Grob's Attack can often lead to 'meme' openings, such as a series of increasingly bold gambits named after fizzy drinks following on from the Double Grob 1...g5 ^[2][3]

• Michael Basman (1989). The Killer Grob. Pergamon chess openings. ISBN 0080371310.
• Claude Bloodgood (2010). The Tactical Grob. Ishi Press. ISBN 487187866X.
• Kasparov, Garry, & Keene, Raymond 1989 Batsford chess openings 2. ISBN 0-8050-3409-9.

Wikipedia has related information at Grob's Attack.