9...a5 Against the Bayonet Attack: The King's Indian Antidote and the Missing Data

On my desk in Guangzhou sits a seven-page document. The first page carries a headline about round two of a team event held in Samarkand, Uzbekistan. The remaining six pages describe a chess opening DVD in which the author promotes Black's ninth move, 9...a5, as an antidote to the Bayonet Attack in the King's Indian Defence. No team, no board, no result connects the two halves.

In my trade, that is the first signal. "People call it a shock; I call it data that has not been read." In this document, however, the unread data sits in the promotional section. A theoretical opening product is being sold on exactly three kinds of argument: a known move, a strategic feeling, and a claim that carries no number at all.

The King's Indian Defence arises from 1.d4 Nf6 2.c4 g6, with Black conceding the centre before counterattacking with ...d6, ...e5 and ...Bg7. The Mar del Plata variation extends that structure with ...Nc6 and ...e5, pushing both sides into a two-wing battle: White storms the kingside, Black floods the queenside. The ECO codes for this branch fall between E97 and E99.

This opening has appeared regularly on elite boards. Garry Kasparov used the King's Indian Defence as a principal weapon in his world championship matches in the mid-1980s, and the Mar del Plata was part of that legacy. In the twenty-first century its share of elite classical games has declined, giving way to systems with lower theoretical risk. It survives as a surprise weapon, not a foundation.

The Bayonet Attack, White's 9.b4, is the most popular and most troublesome answer to the Mar del Plata. White grabs queenside space before Black can organise the counterattack. Black has one orthodox reply: 9...Nh5, which opens the position, forces the lines and commits both sides to an enormous memorisation load.

The DVD on my desk takes a different road. It proposes 9...a5, striking at the b4-pawn instead of opening the centre, and promises a strategic game with few concrete lines and little to memorise. The packaging rests on a clear contrast: after 9...Nh5 the position opens and computer analysis becomes important; after 9...a5 the two sides enter sound positions with very few forced lines.

The first thing I did was look for numbers. The document cites no ACPL figure, no win rate, no draw rate, no sample game. The core point sits here: the claim that "chances are equal" is a positional statement, not a statement about novelty. 9...a5 is not an invention. It is a long-known secondary branch, while the main line remains 9...Nh5. The product's value lies in practicality and psychology, not in theoretical superiority.

The document names no author, no title, no tournament result, no sample game. "Numbers are asceticism: you must give up what is easy before you can see what is true." What is easy here is an appealing story about an antidote. What remains is a secondary branch with no supporting data.

One argument made me pause longest: computers often do not know how to handle these complex strategic positions. That sentence was once correct, and it belongs to the pre-AlphaZero era. Since 2026, with the arrival of neural-network engines, the long-term, closed positions of the King's Indian Defence with few forced lines are precisely the kind of position engines handle far better than the advertisement implies. This is dated marketing language.

The greater risk lies with the buyer. A secondary branch that is already known cannot be an antidote. A well-prepared White player still has play, and in a branch as heavily mined as the Bayonet, anything called an antidote has a short lifespan. "The transfer market is the only place where people pay for unverified numbers." The opening-theory market works the same way, except the currency here is the buyer's study time.

Based on my experience following these games, I will not draw lines the document does not provide. To assess 9...a5 seriously requires exactly three things: modern engine evaluation across a few dozen sample positions, a database of games already played in this branch, and the name and King's Indian record of the presenter. The document supplies none of the three.

It is also worth being clear about whom this product competes with. ChessBase-style opening DVDs survive on curation and narrative structure, because the raw lines already sit free in online databases. Their genuine differentiator is practical steerability, not theoretical superiority. And the line "for players who like to think for themselves, not memorisers" is an identity-based sales angle — it targets the self-image the buyer holds, not the quality of the move.

If this branch really spreads at club level, the next theory cycle will almost certainly bring a White-side answer. The history of secondary branches in the King's Indian Defence shows this repeats on a cycle of months, no more.

The thing worth tracking is not the DVD. It is the database. If 9...a5 shows up in classical games among players rated above 2700, the document's practical argument is partly confirmed. If it stays inside club-level amateur games, this product remains exactly where it belongs: a study tool for amateurs, not a theoretical turning point.

As for that seven-page document, I am keeping it in the drawer. It reminds me that before arguing about a move, a writer must check whether the headline and the body are telling the same story.