The King's Indian and 9...a5: What Antidote Really Works Against the Bayonet Attack?

Three in the morning in Da Nang, and I have rewound the game on my screen seventeen times. Not a 400-metre hurdle race. A King's Indian Defence, Mar del Plata variation. But my eye moves across the board exactly the way it once counted Karsten Warholm's strides at the national stadium in Japan: slowly, repeatedly, hunting for the one moment of broken rhythm on which everything after it depends.

People talk about speed, but what I find is time. In this game, time sits on Black's ninth move.

That night I was reading the promotional material for a chess-opening training course — the kind of product club players buy the way they buy a multi-tool, hoping it will cut through any difficult position. The product promised something specific enough to be suspicious: a reply to the Bayonet Attack, White's fashionable weapon in the Mar del Plata, by means of 9...a5. Not 9...Nh5. A different branch, packaged as an antidote to a disease called Bayonet.

What kept me up was not the move. It was the way it was being sold.

Where the King's Indian sits on Vietnam's chess map

The King's Indian Defence is one of the classic hypermodern systems. Black lets White occupy the centre, then squeezes that centre from a distance with ...g6, ...Bg7 and ...d6. The name India is not just a place. It is a philosophy: concede space to gain structure, concede speed to gain endurance.

The Mar del Plata variation — named for the Argentine coastal city where it was refined during the 2026 interzonal — is the sharpest expression of that philosophy. Moves like ...Nc6 and ...e5 turn the King's Indian from a passive wall into a two-wing race. Black pushes ...f5 against the king; White pushes c4-c5 and b4-b5 against the queen. Whoever arrives first wins. Both sides play on fire.

In Vietnam, the King's Indian has a life of its own. In national junior events it is the choice of children who dislike memorising the Spanish or the Italian. In amateur tournaments in Hanoi and Ho Chi Minh City it is the weapon of players who want a position of exchange. I once sat in a small club on Nguyen Chi Thanh Street, watching two players over forty fight out a Mar del Plata for three hours, and neither of them mentioned an engine once.

That is why the document caught my attention. It was not speaking to grandmasters. It was speaking to those two players.

The Bayonet Attack: a generation unafraid to trade

Then came the Bayonet Attack. White plays 9.b4. A cold but cruel move: it takes extra queenside space, prepares c4-c5, and turns the position into a race in which White holds the edge in time. For decades, ...Nh5 was Black's main answer — a strong, concrete move that forces White to react. It leads to forced lines where memory and calculation decide.

The Bayonet Attack is no joke. It is the voice of a White school that wants to turn the Mar del Plata into a war of attrition in its own favour. Every b4-b5 thrust is a small knife into Black's structure. Black cannot be passive, because passivity in the Mar del Plata means being swallowed square by square.

Over the past decade, the Bayonet Attack has become one of White's favourite approaches, especially at strong club level and among young international masters. Its convenience lies in this: it gives White a clear plan without demanding much creativity. That is also the weakness the product is aiming at.

The product's promise sounds beautiful: if Black knows what he is doing, the position quickly becomes dangerous for White. That is a sales line rather than a technical one. I have heard it many times, in many different products, across thirty-nine years of watching this industry.

9...a5: an old move in new clothing

The core of the product is this: 9...a5 is a known secondary branch of established theory, not a new invention. It challenges the queenside structure White has just built with 9.b4, steering the game into a closed, manoeuvring struggle with fewer forcing lines than 9...Nh5.

The difference between the two choices is not objective value. Both lead to positions that are theoretically balanced. The difference is the character of the position.

9...Nh5 opens the position. It forces the lines to unfurl, turning every move into a question with a concrete answer. This is the kind of position modern engines feel most comfortable in, because everything can be measured in numbers.

9...a5 closes the position. It demands that the player live with ambiguity for dozens of moves, building a long-term plan with no fixed anchor. This is the kind of position many club players fear more than the sharpest forced line, because it offers no ready-made answers.

The document calls this an advantage for players who think for themselves rather than memorisers. It sounds appealing. But the philosophical framing behind it deserves scrutiny.

The human-versus-machine argument is a decade out of date

This is where I want to pause longest, because it reflects a problem much larger than one training course.

The document argues that switching to 9...a5 makes computers less effective, because complex strategic positions confuse engines. That argument is a legacy of the pre-AlphaZero era, and it is badly outdated.

Modern neural-network engines handle the long-term positions of the King's Indian far better than that sentence implies. They do not need a sequence of forcing moves to evaluate a closed position. They evaluate using billions of self-play games. Saying that computers cannot understand these positions sounds wonderful in a club lecture in 2026, but it does not hold up today.

There is a lesson here that I learned from my own career. When I made the series about Nguyen Thi Oanh in 2026, I believed that human-eyed technical analysis could see things machines miss. I was partly right. But by the time I sat in Tokyo in 2026, counting Warholm's strides, I understood that tools cannot replace the eye, and the eye cannot replace the tools. The two have to live together.

The training course picks one side. It picks the human against the machine. That is a marketing choice, not a technical one.

The data gap in a product advertised as precise

In sports data analysis I always look for three things: sample size, comparison baseline, and degree of uncertainty. With this product, all three are empty.

No sample games are cited. No win-draw-loss rate from any database. No engine evaluation for any line. No author's name. No tournament results for the author in the Mar del Plata.

A theory product without data is like a scouting report without video. It may be correct. But the buyer has no way to verify it except faith.

In Vietnam this deserves particular attention, because most buyers of such products are young coaches and amateur players on tight budgets. They pay with real money and study with real time. A promise without data is an uninsured investment.

Why 9...a5 can still be a reasonable choice for some

I do not want to paint a purely pessimistic picture. That would run against the way I work.

There is a group of players for whom 9...a5 is genuinely useful. They are club players rated roughly 1600 to 2026, who have no time to memorise the fifteen forced moves of 9...Nh5, and who feel more comfortable in a position where they can impose their own tempo.

For this group, the product's value is not theoretical correctness. It is usability. A simple plan you understand clearly always beats a perfect plan you forget on move ten.

I have seen this in athletics. Middle-distance runners do not always choose the theoretically optimal tactic. They choose the tactic their body can actually execute under real conditions and real pressure. Chess is the same. Feasibility beats optimality in most club-level games.

A question of information integrity

One detail in the original package made me stop and reread three times.

The document's headline refers to a team event round in Samarkand, with top teams winning. The body below it discusses a chess-opening training course. The two have nothing to do with each other.

This is a serious problem of source integrity. When headline and body do not match, the reader has no way of knowing which part is real and which was spliced in by mistake. For anyone wanting to cite this material — a coach, a journalist, a chess blogger — this is a red warning.

Samarkand is a real chess centre in Uzbekistan, a country with a strong chess tradition. A team event there could certainly exist. But it has nothing to do with 9...a5. The two contents being mixed together shows that the aggregation process failed somewhere.

In my own work I have learned one principle: when a source contradicts itself, check the original before using it for anything.

Black's problem in the engine era

There is a larger question behind the story of 9...a5: does the King's Indian still have a place at the highest level?

My answer, based on what I observe, is yes — but as a surprise weapon rather than a mainstay. The King's Indian's share of elite classical games has fallen in the engine era. Grünfeld, Nimzo-Indian and more stable systems take most of the minutes.

The reason is simple. The Mar del Plata concedes space and invites a sharp struggle in which theory has been excavated to the bedrock. Once both sides have engines, the advantage of careful preparation belongs to the player who chooses the lower-risk system.

But the King's Indian does not vanish. It lives in games where Black needs a position the opponent cannot prepare perfectly. It lives in tournaments where psychology matters as much as theory. And it lives in the hearts of millions of club players worldwide who love it for its character rather than its score.

In Vietnam, I believe the King's Indian will survive at club and junior level. It teaches lessons other systems do not: how to endure pressure in a cramped space, how to counterattack when pushed back, how to trust a long-term plan while everything around you collapses.

What I learned from an over-sold move

In many years in this trade I have seen many things sold in the language of certainty. A tennis player called the successor. A tactic called the turning point. A move called the antidote.

Most of those promises are partly right and partly wrong. The writer's job is not to deny them entirely, but to put them in proportion.

In the silence of the stands, the future wears running shoes. And in an over-sold move I found a small truth: chess players still long for something that makes them feel in control. The product sells that feeling. Not the move 9...a5.

The stands are empty, but the podcast taught me to listen to the game from inside. What I hear here is the voice of a community searching for its own path out of the flood of engine-driven theory.

What Vietnamese players should actually do

If you are a player considering buying such a product, here is how I would approach it.

First, check whether the 9...a5 branch genuinely exists in your database. No need to trust the document. Trust the games that have been played.

Second, ask yourself which group you belong to. If you have time to learn fifteen forced moves, 9...Nh5 remains the mainstream and stronger choice. If you need a reusable position that does not demand perfect memory, 9...a5 may suit you.

Third, cross-check with an engine before investing time. A line can change evaluation overnight.

Fourth, remember that no move is immune to an opponent's preparation. Once 9...a5 becomes popular, White will answer it. Every antidote has an expiry date.

Looking ahead

That night, after closing the document, I sat for another hour and played the Mar del Plata through from start to finish, without an engine.

I did not find an answer. I found a better question: if I were Black, and my opponent were someone thoroughly prepared against the Bayonet Attack, which position would I want — the one where I can calculate every move, or the one where I must trust my own judgement for hours on end?

That is a question no product can answer for me. And it is, perhaps, a question every Vietnamese chess player has to answer for themselves.

From the sandpit runway to the virtual arena — the homeland of sport has no borders. The move 9...a5 is not an ending. It is a fork in the road, and every fork demands a walker clear-headed enough to read the sign before stepping through.