The King's Indian Defense and the Bayonet Attack: Why 9...a5 Is Being Sold as an Escape from the Engine Era

In a tournament hall in Chengdu, I once watched a young player push his b-pawn to b4 on move nine, and the man opposite him — a player who had spent thirty years handling the Black pieces in the King's Indian Defense — raised a hand to his forehead and held the pose for nearly three minutes. He was not really calculating. He was remembering. Remembering whether his preparation file held a move for this position, and if it did, whether that move still stood before the eye of the engine or had long ago been stripped bare. That b4 move carries a name that sounds like a blade: the Bayonet Attack. The Bayonet has never grown old; only the people who answer it have changed.

In 2026, I thought I was stepping onto a stage. It turned out I had only stepped into a corridor. That corridor was longer than I imagined, and it led me into rooms where people did not talk about winning and losing, but about how not to be swept away.

Why b4 is a bayonet

To understand why a small pawn move like b4 makes a player pause, we have to return to the structure of the King's Indian Defense. The game runs 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 0-0 6.Be2 e5 7.0-0 Nc6. This is the Mar del Plata line, the sharpest branch of the whole system, where the two sides divide the board: White masses on the queenside, Black launches a counterattack on the kingside. Black concedes central space in exchange for a counterattack with a rhythm of its own, and that rhythm is what has kept the system alive across so many engine generations.

On move nine, White pushes b4. This is the Bayonet. It grabs queenside space, pushes Black's pieces back, and, more importantly, breaks Black's plan to open the flank by forcing an immediate reply. In recent years the Bayonet has become fashionable again, partly because it poses Black a very heavy preparation problem.

Black's mainstream answer is 9...Nh5. This move opens the position, lifts the knight to the rim, and leads to lines that demand high precision — exactly the kind of thing engines like. For professional players, it is a road already drawn by thousands of games and millions of hours of calculation.

An escape named a5

Yet there is another move. An instructional opening DVD is now selling a solution its author calls the antidote: 9...a5.

The idea is clear. The a5 pawn attacks the b4 pawn that has just advanced, reclaims the initiative on the queenside, and prepares plans such as ...c5 or ...Be6. What is striking is not whether the move is new — it has appeared in top-level practice as a way to gain space and tempo — but how it is packaged. The author is not selling a theoretical edge. The author is selling an escape.

The core point I want to stress: 9...a5 is not a theoretical refutation but a practical offer — trading the memorization of lines for the understanding of plans. The positions it leads to are described as objectively balanced, with very few concrete lines, and tilted toward strategy rather than tactics. In other words, it promises a game one can play with understanding instead of memory.

For whom is this offer valuable? Not for professionals, who meet the Bayonet regularly and keep an entire preparation team. It is for club players, who play by strategic instinct, meet the Bayonet a few times a year, and do not want to spend hundreds of hours memorizing lines that an opponent can erase with a single unexpected move.

This is where I see myself reflected. Based on my experience of watching games across thirty-two years of chess commentary, most players do not lose for lack of opening knowledge. They lose because their opening knowledge is too wide and too shallow. A move like 9...a5, if it truly leads to positions that demand understanding, could be a gift to that group.

The trap lies in the sales pitch itself

But this is where I have to say what a salesman would not.

The central claim of this product — that computers often do not know how to handle the complex strategic positions that arise — is weakening year by year. Stockfish and Leela evaluate the strategic positions of the King's Indian Defense reliably, and they understand better and better those positions once considered a blind spot of the machine. A promise built on the machine's weakness is an asset that is losing value.

Then there is the question of evidence. I went back through the entire promotional material, and what I found was not data but prose. No engine match rate. No average centipawn loss. No database statistics, no sample of games. The claim that 9...a5 is better than, or at least equal to, 9...Nh5 is an assertion, not a proof.

I am not saying the move is wrong. I am saying its practical value is unverified, and in chess the difference between could be right and has been proven is the distance between a belief and a weapon.

After July 2026, I understood that humility is also a tactic. When I mispronounced the name of an Iranian striker three times in one half and fell silent for twelve seconds on air, I learned that the most dangerous thing is not ignorance, but believing one already understands enough. An opening product is the same. It is safe only when the buyer knows its boundaries.

There is one more layer, one that belongs to the craft of making content. The original document I read carried a strange mismatch: the title spoke of a European schools chess championship, from Tsaghkadzor to the grand final, while the entire body discussed a King's Indian Defense opening DVD. The two subjects had nothing to do with each other. For a reader, that mismatch is not a small detail. It is a sign that the reader's trust is being placed in a product whose own packagers had not checked it carefully.

And then there is the format. A physical DVD is an ageing distribution model. Opening knowledge today flows through subscription platforms such as Chessable, through online lessons, through interactive databases that can be updated. A disc cannot absorb the corrections an engine finds after it has been printed. That is a structural disadvantage, not a matter of taste.

And the market? It is a niche within a niche. The Bayonet is only one part of the Mar del Plata line, and that line is only one part of the King's Indian Defense, a system that has itself declined in frequency at the highest level in the engine era. Selling an antidote for a disease fewer and fewer people catch — that is a business problem, not a chess problem.

What remains after all of it

When the stands are empty, I hear the game whisper in another language. I commentated on forty-five games without a single spectator during the season the stadiums fell silent, and in that silence I learned that a position does not need an audience to become real. It only needs the person sitting before it to understand what he is doing.

Whether 9...a5 lives or dies will not depend on how it is advertised, but on whether club players find in it something the engine cannot give them: the feeling that they are playing chess, not retyping a memorized lesson. If it does that, it deserves to exist — regardless of any statistic. If it does not, it is just a wooden bayonet in a war whose fighters switched to other weapons long ago.

So the real question is not whether 9...a5 is stronger than 9...Nh5. The real question is: in an era when engines have read every corner of the board, is there still room for a move chosen because it makes a human feel more at ease, rather than because it is stronger?