The 9...a5 Move in the King's Indian: When an Old Line Gets a New Coat

I keep an old habit from my years analyzing video footage in Da Nang: before trusting any advertisement, I open a database and check first. That night I replayed an old Mar del Plata game. White pushed 9.b4 — the Bayonet everyone knows by heart — and Black calmly answered 9...a5. The friend beside me, a club player, asked immediately: "Is this a new invention?" I shook my head. The move 9...a5 has been in the books for ages. The only new thing is how it has been packaged into an antidote for the fashionable Bayonet, with a loud promise attached: playable without memorization.

That promise hits exactly the itch of most amateur players, the ones crushed by opening theory every time they log into a blitz pool. But it also exposes a blind spot in the chess-publishing industry. To read it properly, you have to set the marketing aside and look at the structure.

An opening system always on the defensive

The King's Indian Defense (1.d4 Nf6 2.c4 g6, followed by ...Bg7) is the classic hypermodern system: Black deliberately concedes the center and then recaptures it. In the Mar del Plata variation (ECO roughly E97–E99), Black develops ...Nc6 and ...e5, leading to a mutual wing attack: White storms the queenside while Black tears the kingside open. It is one of the sharpest lines in classical chess, where one slow tempo can lose the game.

The Bayonet (9.b4) is White's fashionable answer: it grabs queenside space, threatens b4-b5 to drive back the knight, and forces Black to choose. The orthodox reply has long been 9...Nh5 — a move that opens the position, forces concrete lines, and compels calculation from both sides. This is exactly where a chess DVD enters, advertising 9...a5 as a different turn: fewer concrete lines, more strategy, less memorization.

On paper, that is a clever sales argument. It does not promise theoretical superiority, only a sound position with "very few concrete lines." It targets a very specific buyer: the player who prefers to think for themselves rather than memorize.

Test the structure, not the promise

The first problem is technical credibility. Any opening product must answer three questions: how many sample games, what win/draw rate, and how does it hold up against an engine. This advertisement offers no game, no ACPL number, no win rate. It offers only qualitative argument. For someone used to checking data three times before publishing — a habit I learned after once misplacing a corner-kick position — that gap is impossible to ignore.

Second, 9...a5 is not an invention. It is a secondary branch, a sideline the experts know well. So where does its real value lie? In forcing White out of the familiar Bayonet script — one White has spent hundreds of hours memorizing. It is a very practical opening-psychology strike: if you cannot beat your opponent theoretically, pull them out of the theoretical territory they prepared.

This is nothing new at the top level. The strongest players still do exactly this in elite invitationals: pick a rare line from the database, not to win on the move itself but to win on the opponent's clock. The only difference here is that the tactic has been repackaged and sold to club players as a personal weapon.

And this is the most interesting part. The product builds a clear human-versus-engine contrast: 9...Nh5 "opens the position, forces the lines, and makes computer analysis important again," whereas 9...a5 "leads to sound positions with very few concrete lines." The implication is that the machine cannot handle such strategic positions, while a human can improvise. That framing appeals to learners because it turns a weakness in preparation into a virtue: you play with your head, not your memory.

I understand the pull. But I also remember being swept up in similar promises, and the only way out was returning to data. Without a table of numbers, without sample games, a strategic argument — however elegant — remains an argument. It is not yet evidence.

The trap is where nobody expects it

Here I have to be blunt. The line "computers do not understand these positions" is the language of the pre-AlphaZero era. In the current neural-network engine age, machines handle the long-term strategic positions of the King's Indian far better than the advertisement implies. That argument sounds encouraging to learners, but it is dated. It sells the buyer a sense of safety that the engine on their own computer has long since refuted.

I am not saying this to bury a product. I am saying it because it exposes an old mindset circulating in chess publishing: substituting a feeling of safety for evidence. In football, people call that coaching by slogan — thrilling to hear, but unable to survive a single session with the footage.

There is an even bigger blind spot. This entire document is attached to a headline about round two of a team event in Samarkand, while the body discusses a King's Indian opening DVD. Two unrelated texts have been spliced together. For an analyst, a headline that drifts from its body is a red flag about source quality. You cannot cite a document that contradicts itself in its very first line.

That mismatch is not a small detail. It reveals where the content-aggregation process broke down: someone took the headline of a tournament report and pasted it onto the body of a product blurb. For readers, the consequence is not just reading the wrong thing — it is losing the ability to trust the byline. A document, however correct, is useless if you cannot establish who wrote it, when, and on what basis.

The promise of "no memorization" also deserves a skeptical read. The Mar del Plata is inherently sharp and forces calculation from both sides. No branch truly removes calculation from chess. What 9...a5 achieves is changing the type of calculation — from memorization to understanding — not eliminating it. For an amateur expecting relief, the gap between those two things is enough to shatter hope in the very first game.

I once sat in an empty stadium in the middle of the pandemic, where all noise was stripped away and only the bare structure of the game remained. Chess is the same. When you remove the advertising, the sensational headline and the promises, what remains is a board that knows no mercy. 9...a5 may be a good move. But good for whom, at what level, and for how long — that question must be answered with data, not belief.

If there is one thing I keep from dissecting this story, it is this: do not buy a promise, buy a structure you can verify. Demand sample games, demand the author's name, demand engine evaluations before spending money. Chess does not forgive carelessness, and an old line wearing a new coat is still an old line until games prove otherwise.