9...a5 and the Lesson of a Chess DVD: When Surprise Is Sold as Truth

In the Last Three Games

In the last three games I sat with after play at the Binh Duong chess club, two had Black playing the King's Indian, and both were squeezed on the queenside by move eleven. Both players knew 9...Nh5 the way a schoolchild knows the multiplication table, reciting fifteen moves of theory fluently, then stopping in the middle of the board with the look of someone who has just forgotten where he is standing. Mr H., who repairs phones on Phu Loi street, said something I wrote straight into my notebook: "I memorise so I don't have to think, and in the end I still have to think — only now I'm thinking while the clock is running."

A few days later, a chess DVD on the King's Indian arrived at the office. A plastic-wrapped case: no author name, no release date, no product ID, not a single sample game printed on the back. Just one promise — that the ninth move 9...a5 is the antidote to the Bayonet Attack, that it lifts Black out of the forced-theory swamp, and, the line that made me stop longest, that "computers don't understand these positions".

I sat with that case for three evenings. Not to find a way to dismiss it. I sat because it touches the exact sore spot of thousands of Vietnamese club players: they are not short of enthusiasm, they are short of time to memorise, and they get crushed by people who have time. A pitch has a ball in it, and it also has the calluses of a life. So does a chessboard. Behind every pawn is an evening after work, a seventeen-kilometre motorbike ride, a child already asleep when the father gets home.

Why Mar del Plata Is the Last Line

The King's Indian is the opening of people who believe in asymmetry. White takes space on the queenside; Black concedes the centre and strikes back with ...e5, ...f5, ...f4, ...g5 — a flood rolling down from the kingside. The name Mar del Plata comes from the tournament held in the Argentine city of that name in 2026, where the system was dissected and named. Before that, David Bronstein had used the King's Indian as his main weapon in the 2026 world championship match against Mikhail Botvinnik — one of the most beautiful confrontations in chess history, where an artist nearly toppled a logic machine.

Then Robert Fischer played it. Then Garry Kasparov played it and turned it into a manifesto. Across the decades it became an opening people love or hate; few sit in the middle.

The Bayonet Attack, marked by 9.b4, has been White's sharpest answer in several eras. White does not strike at the centre or enter a speed race. White pushes a pawn up the queenside for space, then builds the clamp: b5, Ba3, Nd2, a4. White is telling Black: you may attack the kingside, I will attack the queenside, and I will arrive first because I have more roads.

The position after nine moves, with a White pawn advanced to b4, poses Black a simple and cruel management question: how many hours do you have to study? If the answer is "not enough", then the most correct theoretical advice in the world becomes useless.

That is the market. That is why this DVD exists.

The Ninth Move, and a Gap in the Documentation

I read the product description a fourth time and wrote down what it supplies: no engine evaluation, no average centipawn loss, no game count, no sample line beyond the single move. The move sequence jumps from 7.0-0 straight to 9.b4, silently omitting 7...Nc6 and 8.d5 Ne7.

Those two moves are not detail. Without them the Bayonet does not exist. Someone writing for a reader who is about to sit at a board would not omit them. Someone writing to persuade could.

I do not treat this as a chess error. I treat it as the fingerprint of a genre: advertising copy dressed as analysis. And if I am the buyer, I want to know that before I pay.

The Real Structure of 9...a5

What Black needs after 9.b4 is an answer that does not require remembering twenty moves. 9...a5 gives exactly that answer, and it does what the blurb claims — the blurb simply names it wrongly.

Look at how it operates. The a5 pawn touches b4 directly. White must choose, and there are only two real choices.

One is b5. White clamps, freezes the queenside, takes permanent space. But a frozen queenside also frees Black from worry there. Black has a single direction to play, and it is the direction Black already likes: ...Nd7, ...f5, ...Kh8, ...Rf6, ...g5. No more calculating whether White will open the queenside with c5 or with a4. Everything becomes a one-way race.

Two is bxa5. White opens the queenside — but opens it for whom? Black recaptures with ...Rxa5, and suddenly the rook enters the game without paying a price. An open a-file is a gift. White loses no material; White loses the position.

Both branches lead to the same structural outcome: the position loses its forcing character. Forced sequences become sequences of choice. And that is the crux — 9...a5 does not raise Black's position, it lowers Black's preparation cost. Its true value is a value of time, not a value of advantage.

I have seen this many times in club games. The Black player wins not because he understands more deeply, but because he has less to remember. He has forty minutes for the first eighteen moves; his opponent has forty minutes for a system he must reproduce exactly, exclamation marks included.

The Machine Saw It in 2026

Here I have to be blunt, even though it spoils part of the sales story.

The claim that "computers don't understand these positions" is a legacy claim. It was true in the 2000s. It is no longer true.

In December 2026, AlphaZero beat Stockfish playing closed, locked, space-heavy positions of exactly the kind people called human territory. In September 2026, Stockfish 12 arrived with NNUE evaluation, and since then the machine-human gap in strategic positions has narrowed to the point where "the machine doesn't understand" is nostalgia rather than argument.

What survives is a narrower and genuine point. In positions after 9...a5 there are fewer forcing lines. The gap between human and engine here is a memory gap, not an understanding gap. The engine can still evaluate the position in fifteen minutes. What the engine cannot do is sit in Mr H.'s chair at eleven at night, with forty minutes on the clock and an opponent who prepared three weeks ago.

The difference between "the machine cannot see" and "the machine sees but I cannot remember" is the entire content of this product — and the blurb chose the wrong side.

On "the Chances Are Equal"

The blurb states that objectively the chances are equal. No evaluation accompanies it. No reference game, no database citation. I mark that sentence unverified, and I do not intend to soften it.

Structurally, White owns durable space and a queenside majority — assets that only appreciate as the endgame approaches. Black owns the initiative and a kingside that can explode at any moment. That is a high-variance balance, not a symmetric equality. The two sides are level on points but unequal in the kind of risk they carry.

Saying "the chances are equal" in such a position is like saying two boats are both mid-river. True on coordinates. Wrong on weather.

The Asymmetric-Payoff Problem

This is where I want to linger, because it is the central technical risk of the product and the text does not touch a word of it.

A rare line benefits only the side that has studied it, and the benefit lasts only until the opponent catches up. The half-life of surprise is inversely proportional to the move's popularity. The rarer the move, the longer it lives. The more common it is, the faster it dies — and dies in the worst way: silently, because nobody tells the buyer it is already dead.

There is a detail here the text omits. In the Bayonet, 9...a5 has long sat among Black's principled replies; it is not a stray sideline. It is rare in one database window and familiar in another — rare in club games, well known in prepared games. So the real question for the buyer is not "is this move strong" but "does my opponent consult a database".

If the answer is yes, the surprise has expired before the disc leaves the plastic.

Who Actually Buys This DVD

I drew a small table in pencil, based on what I see at club events and study evenings.

Below 2026 Elo: medium-to-high practical value. Opponents at this level rarely prepare as far as the Bayonet. They play on inspiration and choose safe moves. For them, strategic guidance beats ten pages of memorised theory.

2026 to 2400: this is peak value. Opponents here genuinely prepare, genuinely open an engine, genuinely keep files per opening. A rare move produces the largest surprise dividend, because they have the skill to exploit the gap and too little time to learn fifteen new moves.

Above 2400: value drops clearly. Opponents and their seconds will have the move in their files. The rarity premium collapses and the main line returns to the throne.

The table shows something simple: the product is not sold to weak players and not sold to strong ones. It is sold to the middle — players with enough understanding to exploit a choice-rich position and too little time to need someone to prune those choices.

And it is not sold to players being outplayed positionally. It is sold to players being outplayed on memory. Those are two different pains, and only one of them is cured by a DVD.

The Blind Spot of Collective Memory

There is a beautiful and very stubborn belief in the Vietnamese chess community: that computers are good at tactics and blind at strategy, that closed positions are where human dignity survives. I believed it. I wrote it for years.

But that belief dates from the era when engines evaluated by raw force. It has outlived several engine generations and now exists as a comforting mantra rather than a technical fact.

What the machine truly cannot see is not on the board. It is on the clock. It is in the fact that Mr H. must close his shop at nine in the evening. It is in the fact that Vietnamese club players mostly play rapid and blitz, where a strategy-first system eats far more time than a memorised forcing line.

That is the final paradox, and the text never mentions it: people buy this product to depend less on memory, then take it into exactly the format where memory is king.

Sixty days listening to recordings, I imagined the roar of empty seats. In the spring of 2026, when every tournament stopped, I shut myself in my Binh Duong flat, replayed the second leg of the 2026 AFF Cup final once a night, and learned something no opening book teaches: silence is not emptiness, it is the place where you hear what is actually missing. In the position after 9...a5, what is missing is not a move. What is missing is time.

In a 0-2 defeat I saw another kind of victory: supporters applauding with their whole hearts. Volgograd, June 2026. Fifteen thousand Icelanders stamped and clapped for seven minutes after the final whistle, in a stadium of forty-four thousand. They were not applauding a good move. They were applauding a way of staying. Club players need a way of staying too — and that way is not inside a rare move.

What Remains After the Plastic Comes Off

I am not saying this DVD is useless. I am saying it is useful in a different way than it advertises.

It is useful as a reminder that grassroots chess is a resource-management problem, and the scarcest resource is not rating but the number of evenings a person can give to a board. 9...a5 answers that problem correctly. It simply does not answer the problem the blurb poses.

As for White — the side being targeted — there are three natural replies the text never mentions: b5, Ba3, Nd2. That is the counter-attacking front. Anyone buying a DVD on a defensive system should know their opponent has at least three clear directions, long since analysed. Selling a defensive line without naming the enemy artillery is selling half a truth.

Age does not extinguish love for the board; it only changes its colour. At thirty-seven I no longer sprint down the touchline looking for a rare move. I sit back and ask the questions I did not ask twenty years ago: how many minutes does this move save me, and how many does it take away?

The game ends, but the applause still echoes in my memory. And in that memory, what I remember is not the ninth move. It is Mr H.'s eyes as he rose from the table — the eyes of a man who had just understood that the problem was never that he had not memorised enough moves.

Freeze Frame

The DVD is still in its plastic on the corner of my desk, next to a chipped white pawn I picked up at the club years ago. Tonight, at the club, someone will play 1.d4 again. Someone will answer ...Nf6, and in his head there will be a list of moves he must remember, longer than the list of moves he actually understands.

What I want to tell him is not to skip the purchase. It is to ask the seller one question before the plastic comes off: how many minutes does this move save me, and when does it expire?

If the seller can answer, buy it. If not, leave the disc in the wrap — a cheap reminder that in chess, the only thing that never expires is the time we spend understanding what we are doing.