Pushing the pawns in front of your king after it has castled is a risky tactic. Pawns can only go forward. This means that as they progress, they leave a potential tactical void behind. For the king, the line of pawns are his bodyguards. They are a powerful line of defence against threats to the king. And just like real bodyguards, if they advance forward and move away from their master, their effectiveness in providing defence is substantially diminished.

This was well demonstrated in this game. I played White and we began with a Vienna Game. My opponent defended on the second move with (2… d6), a relatively suboptimal passive approach, but not one I knew how to exploit. By move 9, we entered the middle game with opposite-side castling and equality according to Stockfish [0.00].

This equality was mostly kept for the next handful of moves, until on move 16, my opponent played (16… g6). I think that their logic was they wanted to prevent my knight from advancing to the f5 square. However, as per the opening paragraph, this substantially weakened the defence of their king. Stockfish called this move a blunder and the evaluation shifted from [0.00] to completely winning for White [+4.27].

Black moving their g-pawn created a defensive deficit, a “void”, of the dark squares surrounding their king. This allowed for an overwhelming attacking plan. Firstly (22. Nh6+) forced Black’s dark square bishop to trade itself away to prevent checkmate. This then allowed my bishop and queen to gang up for another checkmate threat on the dark squares. My opponent was able to deflect this by advancing yet another of the king’s pawns (23… f6). However, my h-pawn had marched into the king’s territory and tore apart the last of the king’s bodyguards with (24. hxg6) and then (25. gxh7+). With my queen and rook as a battery on the now fully open h-file, it was ladder mate in a couple of moves.

Game on chess.com: https://www.chess.com/game/live/58512043831

[Event "Live Chess"]
[Site "Chess.com"]
[Date "2022.10.03"]
[Round "-"]
[White "vitualis"]
[Black "lefty9897"]
[Result "1-0"]
[Timezone "UTC"]
[ECO "C25"]
[ECOUrl "https://www.chess.com/openings/Vienna-Game-2...d6"]
[UTCDate "2022.10.03"]
[UTCTime "05:02:22"]
[WhiteElo "1355"]
[BlackElo "1375"]
[TimeControl "1800"]
[Termination "vitualis won by checkmate"]
[StartTime "05:02:22"]
[EndDate "2022.10.03"]
[EndTime "05:24:19"]
[Link "https://www.chess.com/game/live/58512043831"]

1. e4 e5 2. Nc3 {Vienna Game} 2... d6 {Defending with d6 is a relatively suboptimal passive approach [+0.54]} 3. d4 exd4 4. Qxd4 Nc6 5. Qe3 Nf6 6. Bb5 Bd7 7. Bxc6 Bxc6 8. Bd2 Be7 9. O-O-O O-O {At the end of the opening, we have an exciting position with opposite side castling and equality [0.00]} 10. h3 {Stockfish prefers developing the other knight first rather than the immediate king-side pawn storm} 10... Re8 11. g4 Bf8 12. f3 Nd5 $4 {A blunder [+0.11] from [-2.47]. This permanently weakened the defence of the king. Stockfish prefers d5 to pressure the centre or a queen-side pawn push.} 13. Nxd5 Bxd5 14. Ne2 Bc6 $6 15. Nd4 Qd7 16. Bc3 g6 $4 {[%c_arrow
g7g6;keyPressed;none;from;g7;opacity;0.8;to;g6;persistent;false] A serious blunder [+4.27] that creates a major weakness in the dark squares around the king. This move creates the opportunity to results in White's winning attack on the black king.} 17. Kb1 Re7 18. h4 Rae8 19. Qg5 Re5 20. Nf5 {[%c_arrow
c3e5;keyPressed;none;from;c3;opacity;0.8;to;e5;persistent;false,d1d7;keyPressed;none;from;d1;opacity;0.8;to;d7;persistent;false,f5h6;keyPressed;none;from;f5;opacity;0.8;to;h6;persistent;false,h6g8;keyPressed;none;from;h6;opacity;0.8;to;g8;persistent;false][%c_highlight
e5;keyPressed;none;opacity;0.8;square;e5;persistent;false,d7;keyPressed;none;opacity;0.8;square;d7;persistent;false,h6;keyPressed;none;opacity;0.8;square;h6;persistent;false]
A powerful move [+4.36] which blocks the rook's attack on the queen, creates a discovered attack on the rook by the bishop, and brings another piece attacking Black's king} 20... R5e6 21. h5 {Bringing another attacker and Black's king's defences are about to be torn open...} 21... Qd8 22. Nh6+ {[%c_arrow
h6g8;keyPressed;none;from;h6;opacity;0.8;to;g8;persistent;false,c3h8;keyPressed;none;from;c3;opacity;0.8;to;h8;persistent;false][%c_highlight
g8;keyPressed;none;opacity;0.8;square;g8;persistent;false,h8;keyPressed;none;opacity;0.8;square;h8;persistent;false,g7;keyPressed;none;opacity;0.8;square;g7;persistent;false]
This forces the trade of Black's dark square bishop and the weakness of the dark squares around the king is now fully revealed} 22... Bxh6 23. Qxh6 {[%c_arrow
h6g7;keyPressed;none;from;h6;opacity;0.8;to;g7;persistent;false,c3g7;keyPressed;none;from;c3;opacity;0.8;to;g7;persistent;false][%c_highlight
g7;keyPressed;none;opacity;0.8;square;g7;persistent;false] Black must respond to the checkmate threat} 23... f6 24. hxg6 {[%c_arrow
h6h7;keyPressed;none;from;h6;opacity;0.8;to;h7;persistent;false,h1h7;keyPressed;none;from;h1;opacity;0.8;to;h7;persistent;false][%c_highlight
h7;keyPressed;none;opacity;0.8;square;h7;persistent;false] This opens the h-file, creating another checkmate threat} 24... R8e7 25. gxh7+ {And the Black king is now completely exposed [+M7]} 25... Rxh7 26. Qxh7+ Kf8 27. Qh8+ Ke7 28. Rh7# {[%c_effect b1;square;b1;type;Winner,e7;square;e7;type;CheckmateBlack]} 1-0