9...a5 Against the Bayonet: A Strategic Sideline and a Crack in Opening-Product Trust

October night in Saint Petersburg. Rain taps lightly on the wooden window frame, and I am reading the description of a chess DVD. I do not remember the cover, the seller, or the price. But I remember one line, in bold, placed in the middle of the page: “Computers often do not know how to handle this position.”

That line made me pause longer than usual. In forty-nine years of watching the board, I have heard it many times, in many places. Long ago, people said it to one another at Mar del Plata, when games opened onto two wings as wide as steppes waiting for horses, and when leading players still believed there were positions before which machines had to bow. Today, the same thing is said in a short advertisement, with not a single game attached.

I turned off the screen, poured tea, and thought: perhaps this is the real story of modern chess learning material. Not the story of a new move, but the story of what is sold to the learner, and what is kept behind the cover.

To understand why that move deserves discussion, a little context is needed.

The King’s Indian Defense begins with 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7. Black concedes the centre, lets White build a large structural block, then seeks counterplay on both wings. It is the opening of the patient. But the Mar del Plata Variation — with ...e5 and ...Nc6 — is the least patient corner of that opening: the centre closes, both sides advance on the wings, and usually whoever arrives one tempo earlier wins.

In that variation, the Bayonet is White’s 9.b4 push. One move only, but it seizes queenside space before Black can stabilize. White keeps c4 and c5, then opens the queenside with a4 and file pressure. Black cannot simply wait. And the oldest traditional answer — 9...Nh5 — is the most expensive answer in terms of memory.

Why expensive? Because after 9...Nh5, both sides enter a near-forced sequence. People call these forced lines — one wrong move and a piece is lost. At elite level, thousands of engine hours have been poured into them. At home, a learner opens a database and sees a variation tree hundreds of lines deep, each line branching further. Memorizing it all is a matter of memory; understanding it all is a matter of a lifetime.

That is fertile ground for products like that DVD. They do not sell the truth of the opening. They sell a detour. White pushes the Bayonet because White wants a concrete, prepared fight. Black, unwilling to enter that fight, needs another route. The question is whether that other route truly exists, or exists only in the advertisement.

The product proposes 9...a5.

First, let it be said clearly: this is not a new move. It is an established strategic sideline, occasionally seen in club practice, but it has never occupied the mainstream position held by 9...Nh5. What matters is how it is framed.

Instead of entering the whirlwind of 9...Nh5, Black plays 9...a5, keeps the queenside structure intact, prepares ...c5 or ...c6 depending on circumstances, brings the knight to ...Ne8 and then ...f5, and hands White the reverse problem: to create space without knowing exactly where to open it.

In other words, 9...a5 is a way of giving the choice back to White. This is the subtle point advertising usually skips. A move is not good because it wins. A move is good because it forces the opponent to take responsibility.

A player experienced with King’s Indian structures will recognize in 9...a5 something familiar: a balanced position that is anything but simple. No move is forced. In exchange, every move must be chosen. That is precisely where the two approaches diverge most.

Let us compare on three concrete dimensions.

First, the memory burden. With 9...Nh5, a Black player on average must carry a complex body of variations, often dozens to hundreds of lines depending on opponent level. With 9...a5, that body is far smaller. The price is not paid in memory but in structural understanding. Without memory, you can still calculate. Without understanding, you have nothing to hold on to.

Second, execution stability. For club and amateur players, I assess 9...a5 as fairly stable, because it demands fewer precise sequences. Against a well-prepared elite opponent, that stability drops sharply — at that level, 9...a5 is a known sideline, and White’s analysis teams usually have answers ready.

Third, surprise value. This is the real asset of 9...a5, and the most perishable. The more widely a sideline is used, the less surprising it becomes. If that product succeeds at club level, its very success will erode its advantage.

What I want to stress is this: the true value of 9...a5 is not that it is stronger than 9...Nh5, but that it shifts the problem from memory to understanding — a shift suited to the majority of amateur players, yet one that does not alter the theoretical foundation at the elite level.

There is another detail rarely mentioned. The King’s Indian Defense was once a principal weapon for a generation of top players, especially in an era when games were decided by strategic endurance rather than by engine match rate. Today its elite share has declined. But at club level it remains healthy — because it gives a player the feeling of playing a plan, not of replaying a script.

And that feeling is exactly what opening-learning material always tries to sell.

At this point I recall a winter evening in 2026, when tournaments in Russia were suspended and I sat alone in an empty newsroom. That night I wrote about an old European Championship final, and I understood something: when the stadium no longer has a ball, memory begins to score. The chessboard is the same. When no real game remains for comparison, people start believing what they are told.

And that is why the next part of this story matters no less than the technical part.

Now to the difficult part.

The phrase “objectively, chances are equal” in the product description is not a technical conclusion. It is a marketing promise. There is no win rate, no average centipawn loss, no engine match rate, no single sample game. If this were a match report sent to my desk, I would return it with one line: data required.

The transfer market is where people sell the future to buy hope — I once wrote that about football. The opening market is the same. People sell a detour to buy a little reassurance.

But there is another flaw, outside the board, and heavier. The document I received for analysis has a severe mismatch between title and content. The title speaks of a round in Samarkand, of Uzbekistan continuing to dominate and extending the lead. The entire content beneath is an opening product about the King’s Indian Defense. Not one line mentions Samarkand, Uzbekistan, round seven, or any player.

This is not a small matter. For the reader, it is a crack in the chain of trust. For the writer, it is a reminder that when data passes through too many hands, a title can be attached to the wrong content and no one checks.

I must add this in fairness. That mismatch does not make 9...a5 wrong. It only makes the story around it suspicious. And in my profession, a correct conclusion presented with a faulty source is still a conclusion not yet usable.

In closing, what I want to leave behind is not 9...a5.

That move may be good. It may suffice for a club player, and may be a wise detour for someone with no time to study long lines. But the larger question is this: when opening knowledge becomes a product sold by the disc, what remains as data, and what is merely hope carefully packaged? On the day the heart stops, I learned to beat slower but deeper — and perhaps the chessboard, too, deserves to be taught that way.