Editing Grob's Attack (section)

==Responses==
IM [[Michael Basman]] and [[Grandmaster (chess)|Grandmaster]] [[Spyridon Skembris]] are advocates of the opening. It has a certain surprise value, and the average player is unlikely to know how to refute it and more likely to get overconfident and make mistakes. Moreover, the lack of theory along this line may negate the repertoire of an experienced opponent. Intuitive play by  Black can lead into dangerous traps.  Many of these traps rely on Black's replying with 1...d5, attacking the pawn with his {{chessgloss|queen's bishop}}. White can sacrifice the pawn with 2.Bg2 Bxg4 3.c4 with Qb3 to follow, giving White some pressure against the weakened squares d5 and b7.
{{clear}}

{{col-begin|width=auto; float:left; clear:left}}	
{{col-break}}
{{Chess diagram small
| tleft
|
|rd|nd|  |qd|kd|bd|nd|rd
|pd|pd|pd|  |pd|pd|pd|pd
|  |  |  |  |  |  |  |  
|  |  |  |pd|  |  |  |  
|  |  |pl|  |  |  |bd|  
|  |  |  |  |  |  |  |  
|pl|pl|  |pl|pl|pl|bl|pl
|rl|nl|bl|ql|kl|  |nl|rl
| After 1.g4 d5 2.Bg2 Bxg4 3.c4
}}
{{col-break}}
{{Chess diagram small
| tleft
|
|rd|  |  |qd|kd|bd|nd|rd
|pd|bl|pd|nd|pd|pd|pd|pd
|  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  
|  |  |pl|pd|  |  |bd|  
|  |  |  |  |  |  |  |  
|pl|pl|  |pl|pl|pl|  |pl
|rl|nl|bl|ql|kl|  |nl|rl
| After 3.c4 d4 4.Bxb7 Nd7
}}
{{col-break}}
{{Chess diagram small
| tleft
|
|qd|  |  |  |kd|bd|nd|rd
|pd|  |pd|nd|pd|pd|pd|pd
|  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  
|  |  |pl|  |  |  |bd|  
|  |  |  |pd|  |pl|  |  
|pl|pl|  |pl|pl|  |  |pl
|rl|nl|bl|ql|kl|  |nl|rl
| Romford Countergambit, after 5.Bxa8 Qxa8 6.f3 d3{{chesspunc|!}}
}}
{{col-end}}
{{clear}}

Black is not obliged to give White these opportunities. In response to Grob's Attack, Black may also play 1...e5. Good responses would be 2.Bg2 (dominating the light-squared centre diagonal) or 2.c4, the English Variation, preparing Nc3 to solidify White's control of d5. After 1...e5, Black can take aim at the h4-square, left weak by White's pawn advance.  2.Bg2 h5 will force a weakening of White's pawn structure. 2.d3 (intending to answer 2...h5 with 3.g5) or 2.h3 can be answered by 2...Ne7 with the threat of ...Ng6 followed by ...Nf4 or ...Nh4, disrupting White's kingside [[fianchetto]].<ref>{{cite web |last=Martin |first=Andrew |year=2004 |title=How To Meet The Polish & Grob |url=http://www.jeremysilman.com/chess_bits_pieces/041001_h_t_,mt_plsh_grb.html |archive-url=https://web.archive.org/web/20120229232111/http://www.jeremysilman.com/chess_bits_pieces/041001_h_t_,mt_plsh_grb.html |archive-date=29 February 2012 |publisher=www.jeremysilman.com }}</ref>

{{Chess diagram small
| tleft
|
|rd|nd|bd|qd|kd|bd|nd|rd
|pd|pd|  |  |  |pd|pd|pd
|  |  |pd|  |  |  |  |  
|  |  |  |pd|pd|  |  |  
|  |  |  |  |  |  |pl|  
|  |  |  |  |  |  |  |pl
|pl|pl|pl|pl|pl|pl|bl|  
|rl|nl|bl|ql|kl|  |nl|rl
|Keene Defense: 1.g4 d5 2.h3 e5 3.Bg2 c6
}}
Another frequently used setup for White in the Grob is 1.g4, 2.h3, and 3.Bg2. A Black counter-setup might be 1...d5, 2...e5, and 3...c6 (these moves may be played in any order), which, if used in conjunction with an eventual ...e4, negates White's {{chessgloss|king bishop}}'s influence over the centre. IM [[Richard Palliser]] advocates instead the classical setup 1...d5, 2...e5, 3...Nc6, on the grounds that White is more likely to be familiar with the "reversed French" lines after 3...c6 4.d4 e4 5.c4 etc.<ref name="Palliser">{{cite book |last1=Palliser |first1=Richard |title=Beating Unusual Chess Openings|date=2006 |publisher=Everyman Chess |location=London |isbn=978-1-85744-429-2 |page=112}}</ref>

A key element of the Grob is deploying the king's bishop on g2 and having it [[Fianchetto|rule the diagonal]]. In order to further this goal, White must keep the centre clear of pawns. This leads to frequent "tearing at the centre" with c4 often being White's third move.

Due to the unusual pawn structure White attains by playing g4 and c4 so early in the game, there is frequently little advantage to [[castling]]. Play often devolves into a wild and wide-open game, with a definitive advantage usually resolving itself in the first 20 moves.

Responses other than 1...d5 and 1...e5 are rarely encountered in serious games, though some such as 1...c5 and 1...Nc6 are reasonable.
{{clear}}

=== Critical Lines In Engine Play ===
Leela, Stockfish, and Komodo have all failed to hold the Grob against engines of similar strength.<ref>{{Cite web|url=https://wiki.chessdom.org/TCEC_Season_18_This_is_not_a_SuFi_Bonus_Game_39:_LeelaCPU-Stockfish|title=TCEC Season 18 This is not a SuFi Bonus Game 39: LeelaCPU-Stockfish}}</ref> 

After 1.g4 d5 white has five main moves;

*Bg2, pressuring the h1-a8 diagonal.
*c4, preparing Qb3xb7 and undermining d5.
*g5, moving the pawn out of harm's way.
*e3, leading to [[French Defence|French]]-type structures.
*h3, defending g4.

2. Bg2 or g5 is played in the vast majority of games as e3 and h3 surrenders the initiative and leads to inferior versions of more common openings. 2.c4 usually transposes to 2.Bg2 main lines but does give both Black and White a few options for unique sidelines.

==== Grob's Gambit, 2.Bg2 Bxg4 3.c4 ====
Against the Grob Attack's main line, Stockfish has opted to keep the initiative by giving back the b7 pawn as Black. After the moves 3... c6 4.Qb3 e6 5.Qxb7 Nd7 Black has gained a secure King and lead in development.

{{Chess diagram|fen=r2qkbnr/pQ1n1ppp/2p1p3/3p4/2P3b1/8/PP1PPPBP/RNB1K1NR|align=tleft}}

Due to White's overextended Queen and general lack of coordination, Black retains a potentially decisive advantage. c6 is a [[poisoned pawn]] as Qxc6 would be met by Rc8 and Rxc4.<ref>{{Cite web|url=https://wiki.chessdom.org/TCEC_Season_18_This_is_not_a_SuFi_Bonus_Game_39:_LeelaCPU-Stockfish|title=TCEC Season 18 This is not a SuFi Bonus Game 39: LeelaCPU-Stockfish}}</ref>

==== 2. g5 Gambit ====
An alternative attempt to save White's game is to gambit the d4 pawn in exchange for rapid development with 1.g4 d5 2.g5 e5 3.d4 exd4 4.Nf3 c5. This line has been explored in a widely cited theoretical correspondence game on the TalkChess forum.

{{Chess diagram|fen=rnbqkbnr/pp3ppp/8/2pp2P1/3p4/5N2/PPP1PP1P/RNBQKB1R|align=tleft}}

However, after 5.Bg2 Ne7 6.c3 dxc3 7.Nxc3 Nbc6 8.0-0 d5, Black still retains a possibly decisive advantage.<ref>{{Cite web|url=https://talkchess.com/forum3/viewtopic.php?p=825830#p825830|title=Dylan Sharp Vs. Harvey Williamson (G4)}}</ref>