9...a5 Against the Bayonet Attack: A Strategic Answer and the Gaps Nobody Filled

I stayed behind after work, opened the board on my screen, and played White's ninth move exactly: b4. The pawn advances, hits the queenside, and the room goes quiet as if someone just pushed a piece into an empty square in the middle of the board. In the Mar del Plata variation of the King's Indian Defence, the move 9.b4 is called the Bayonet Attack, the spear. It does not ask what you think. It asks how far you have prepared.

That same week, a training product appeared on the chess DVD market, promoting 9...a5 as the antidote to that spear. What made me stop was the headline: it read "Samarkand R2 (open)", a round report from a team event in Uzbekistan, while the entire body of the text discussed an opening DVD. The title and the content belong to two different documents. For anyone who works with data, that is the first marker to note, before a single move is discussed.

CONTEXT: THE SPEAR AND TWO ANSWERS

The position begins with 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5 7.O-O Nc6 8.d5 Ne7. Black concedes the centre from the start, builds a defensive shell around the king, and then counterattacks with ...e5. White pushes the pawn to d5, locks the centre, and both sides race to attack opposite wings. This is the Mar del Plata variation, inside the ECO E97-E99 range, one of the sharpest systems in modern chess.

White's 9.b4 launches the Bayonet Attack: White gains queenside space, threatens b4-b5, and clears the way for the c4-c5 pawn push. Black's orthodox reply is 9...Nh5, a knight to the rim, opening the position, forcing concrete lines, and obliging both sides to remember. The move 9...a5 that the product promotes is a different branch: Black's queenside pawn strikes directly at b4 and steers White into a closed, slower game that demands structural calculation more than memorised sequences.

One point must be stated immediately: 9...a5 is a known branch, not an invention. The product does not claim a novelty. It claims something else, that chances are equal, that there are very few concrete lines, and that if Black knows what to do, things quickly become dangerous for White.

ANALYSIS: WHAT IS ACTUALLY BEING SOLD HERE

Strip away the marketing and the argument is built from four linked propositions. The opening proposition says 9...Nh5 opens the position, forces the lines, and makes computer analysis important again. The next claims 9...a5 leads to sound positions with very few concrete lines. The one after that asserts computers often do not know how to handle the complex strategic positions that arise from this branch. The remaining proposition positions the product for players who like to think for themselves, not for memorisers.

That positioning proposition is the sales proposition, and it targets a specific buyer identity. The approach works well in the opening market, where every product promises something similar. But it also raises a question about the structure of intellectual cost: moving from forcing lines to strategic lines does not delete the study load, it only changes its shape. Memorising 9...Nh5 is measured in lines. Understanding 9...a5 is measured in hours spent analysing pawn structures, weak squares, and deployment rhythm. For most club players, the second kind is harder to train, has fewer clear stopping points, and cannot be checked quickly before a game.

The computer proposition is out of date. Since neural-network engines replaced the traditional evaluation generation, computers handle long-term King's Indian positions far better than the advertisement assumes. The AlphaZero games published in December 2026 made this plain: the machine played positions earlier generations judged unclear, and played them in the language of structure rather than the language of a move tree. The "computers do not understand" argument is a relic of the pre-AlphaZero era, recycled as a commercial advantage. Technically, it no longer holds.

The third notable point: not a single metric is provided. No ACPL, no win rate, no draw rate, no sample games, no author name, no competitive results of the author in this very line. In almost any other professional field, a product published that way would be asked for verifiable data within hours. In chess it still sells, because buyers judge by feel more than by tables.

Here I have to describe my own method. For every opening system I track, I keep a dedicated folder, take notes in my own shorthand, and review games three times: first for the overall flow, second when the centre-controlling side holds the initiative, third when the initiative flips. A diagram helps me remember, but the gaps between diagrams are what decide. With 9...a5, that gap is a problem the promotional text never answers: once White is forced to choose between holding the b4 pawn and opening lines, which structure actually appears, and who is responsible for it?

From a market angle, this is a textbook opening product: it sells an answer to a popular line. The Bayonet Attack is popular at club and master level, so the demand is real. But the product's real value depends on something no advertisement measures: which group the buyer belongs to. An international master already used to structural analysis may extract a few ideas. A recreational player who believes the "few concrete lines" promise will buy the product and discover that calculation is still required.

THE CONTRARIAN ANGLE: THE BLIND SPOT IS ELSEWHERE

The product's biggest blind spot is not 9...a5. It is the assumption that the opponent stands still. Every opening branch is a two-way exchange: once an antidote is widely promoted, it automatically loses part of its value, because White reads the same material. In the Bayonet line, where data is open and high-level games are published within hours, that cycle runs far faster than in the era when theory circulated only in printed magazines.

The second blind spot concerns how the text itself is packaged. A headline about a team round in Samarkand attached to a DVD advertisement is an editing failure. It is also a signal about the content production chain: source splicing, cross-checking, and metadata verification are weak. Pushed out into the corridors of the 2026 AFC Cup because there was no seat for a woman, I learned to read a match from what others leave behind. Here, what is left behind is broken metadata. The press room had no place for me. Tactical history always does.

The third blind spot: the promise of being for players who think for themselves sounds like a virtue, but in practice it is a stricter demand. It asks buyers to take responsibility for positions with no standard answer. Not everyone wants that burden, and the number who quit halfway is probably larger than the number who finish.

WHAT TO TRACK

With an opening branch, the answer always lies in competitive data, in classical games rated above 2700, where both sides are well prepared. I will track three signals: how often 9...a5 appears in open events, whether 9.b4 keeps its fashionable status, and whether the author's identity is published alongside sample variations with engine evaluations. Until then, this product remains an unverified offer. The person standing at the edge of the pitch sees the whole match, not only what is inside the goal frame. I believe in the diagram, but I believe more in the gaps between diagrams. And that gap, this time, remains unfilled.