9...a5 in the King's Indian Defence: a cure that has not been verified

A NIGHT UNLIKE ANY OTHER Two in the morning, 22 February 2026, Nha Trang. The screen was still glowing in the small room facing the sea, and the line kept blinking: “A night unlike any other.” Below it were a few sentences describing a repertoire package for Black in the King's Indian Defence, Mar del Plata branch, after White's ninth move. The seller promised Black a remedy called 9...a5. I sat still for a long time before pressing play. Thirty-two years of chess commentary for VTC taught me something awkward: the most memorable thing in a game is rarely the advertised move; it is the moment someone finds a move nobody suggested. Those same years taught me that every promise printed on a cover must be interrogated to the end, including the kindest promises. WHY THE NINTH MOVE MATTERS The King's Indian is the strangest system I have followed in nearly half a century in this trade. Black voluntarily concedes space, lets White build a large pawn mass, then waits patiently for that mass to lose its balance. The Mar del Plata branch was born from that philosophy: White pushes d5 to lock the centre, then pushes b4 on the queenside. The move 9.b4 is nicknamed the Bayonet Attack. The name is not a joke. Through the 1980s and 1990s, every time White pushed b4 in this structure, my small studio went quiet. You could feel an infantry charge: White's pawns advancing while the supply lines lagged behind. A calm Black counterattacks in the centre or opens a queenside counter-offensive; a rattled Black loses the game. The King's Indian games of Karpov and Kasparov in that era were lessons in patience, not lessons in memory. So the headline is not meaningless. “A night unlike any other” evokes the night assault, and it is decent wordplay. What I dislike is that it stands in place of information. Before dissecting the move, I have to state what readers deserve to know. At the time I watched it, this package named no author, gave no publication date, cited no reference games, offered no engine statistics, and sourced none of its technical claims. In a field where any move can be checked in seconds, a single-source commercial product puts itself in a position where it must prove more, not less. THE MOVE AND THE PRICE OF SIMPLICITY The position begins with a familiar sequence: 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 0-0 6.Be2 e5 7.0-0 Nc6 8.d5 Ne7 9.b4. White has pushed the pawn to b4, hitting Black's queenside structure and preparing Ba3 along the a3–f8 diagonal. Black must choose immediately: strike in the centre or strike on the queenside. The main line of modern theory is 9...Nh5. The knight goes to the rim, attacks f4, prepares ...f5, and stands ready to hop to f4. It is a highly forcing option: White must respond, each response opens a concrete branch, and that is precisely why modern engines are most comfortable here, where everything can be calculated. The package proposes the opposite: 9...a5. Black strikes at the base of the pawn White has just advanced, prepares ...axb4, ...c5 or ...c6, and postpones every decision on the kingside. The idea is to play by plan rather than by variation. It is a familiar approach for those who enjoy handling Black in closed positions, where a move's value lies not in how strong it is but in how many possibilities it opens over the next ten moves. This is both the greatest strength and the greatest weakness of the product. Strong, because the move exists in high-level practice; it has appeared in tournaments and nobody disputes that it is legitimate. Weak, because it is not new. The seller calls it a cure, but a move already present in databases cannot be a cure; it is only a less-travelled turn. The author himself concedes that chances are equal, and that concession quietly reveals the product's real value: the value lies in preparation asymmetry and in surprise, not in objective superiority. Buyers are not paying for a better move; they are paying so that their opponent is not ready. That is a real value, but a conditional one: it exists only if the buyer's foundation is solid enough not to get lost in the unfamiliarity of the new plan. I once spent two months listening to an 18-year-old named Nguyen Van Hai talk about his torn shoes, after he ran 400m in 47.80 seconds at a grassroots meet in Nha Trang in 2026 and was dropped from the provincial squad for lack of training funds. The clip I shot on a phone reached 200,000 views in a month, and a local business then agreed to sponsor him. In the age of the 30-second video, I spent three months hearing a man talk about a 400m race from 2026. What requires patience cannot be shortened by a click, and what is shortened too far leaves gaps. WHAT ARE THE GAPS? The first gap is the claim of “very few concrete lines.” A Black repertoire built on 9...a5 must still answer two large questions. If White does not push b4 but plays 9.Ne1, 9.Nd2 or 9.Bg5, what does Black do? Those branches dominate club-level practice, where opponents sometimes choose the safe move over the sharp one. And if after 9...a5 White steers back into familiar structures from 9...Nh5, does Black know the main lines well enough to hold? Buyers need that before paying, and the promotional material is silent. Another gap lies in the engine claim. The promotion stresses that computers often cannot handle such complex strategic positions. That was once true, in the era of older engines. Since 2026, as neural-network engines have replaced traditional search methods, the evaluation of closed, manoeuvring positions has become far more reliable. An advertising line that outlives the reality it describes becomes misleading, even if the writer did not intend it. The scope of the product remains a blank. Does the package cover only the 9.b4 branch, or the entire King's Indian complex after 7...Nc6? That determines the buyer's real preparation cost, and it is not stated. A club player spending a few evenings learning one branch will feel very different from one who believed he had bought the whole system. The target audience also needs naming. The phrase “suits players who like to think for themselves instead of memorising long variations” is a positioning statement aimed at club and improving players. At that level it is useful and honest. At elite level, nobody can abandon forcing main lines on principle alone. WHERE IS THE BLIND SPOT? Stop at dissecting the move and you miss the more interesting part. The blind spot is chess publishing culture. We are used to buying opening material without asking who the author is, where the data comes from, and how the claims were verified. We accept that nowhere else. When I made a documentary about the 800m runner Nguyen Thi Minh Phuong, who once ran 1:58 and was removed from the 2026 Olympic squad list because of an administrative slip, I had to call twelve veteran athletes of her era to piece the memories together. The performance was real, the person was real, yet it appears in no official list people consult daily. A move follows the same path. A plan can exist in practice, but if it is not recorded with names, events and dates, it lives by word of mouth. Word of mouth is the best environment for legend, not for knowledge. There is a subtler temptation worth naming. “Think for yourself instead of memorising” sounds lovely. It gives learners the feeling of playing like artists rather than machines. Vietnamese fans in Russia were not watching football; they were watching themselves in every pass — and someone buying an opening package is doing the same, buying an image of himself. But in practice, thinking for yourself without a main-line foundation usually becomes an excuse for careless preparation. Strong players do not choose between memory and thought; they use memory to buy time, then use time to think. And surprise? It is real, but its lifespan is far shorter than thirty years ago. A novelty in the 1980s could live five or six years because information travelled slowly. A novelty now, when every game from every open is posted within hours, lives a few weeks. Selling a product based on surprise is selling goods with an expiry date, and the seller should state that date. The stadium is empty, yet the applause of 2026 still echoes inside every old record. Back then, when all sport stopped, I cleared a storeroom and found a VHS tape about Minh Phuong. Forgotten sporting memory is quiet; it simply rests in a drawer until someone opens it. A forgotten move does the same, except its drawer is a database, and nobody opens it. A record never grows old; it is only waiting for someone who knows how to listen. So I do not object to the package. I object to how it introduces itself. A legitimate fallback plan can easily be worth a few dozen dollars to a club player whose regular opponents push b4. But calling it a cure, while the author himself concedes equality, is systematic exaggeration. And systematic exaggeration, repeated often enough, becomes the standard of an entire publishing trade. For me, the argument is not whether 9...a5 is good or bad. The argument is whether we can build a habit of demanding an author, a publication date, reference games and data sources for every opening claim. If we can, good products will be trusted more, and loud products will quietly shrink. I am sixty-five this year. I no longer have time to read everything new, so I choose to read more slowly and ask more. That has a cost: I miss a few fashionable trends. It also brings me to people I would never have met had I hurried. Every chessboard I have sat at holds a secret door, and the entrance is always a person. This time, that person still has not told me his name.