The 9...a5 Move and Four Data Gaps on a King's Indian DVD

A September afternoon in Nha Trang, heavy rain drumming on the tin roof of the chess club on Nguyen Thien Thuat Street. A nineteen-year-old student set a scratched plastic DVD case on the table and asked whether he should buy it. I turned it over. No author's name. No release year. Not a single sample game listed. Just one promise: this move will drag your opponent out of the books, and the buyer will get to "think for himself instead of memorizing." I sat quiet for a while. Thirty-two years of commentating chess for VTC taught me that a training product without a named teacher is usually hiding something — not a conspiracy, but a lack of confidence in its own academic standing. This time, though, the cover named one specific move, so I could check it myself instead of believing.

The stands are empty, but the applause of an old game still rings inside every line. I agreed to look at that DVD to test whether an opening advertisement can stand up on the board.

The King's Indian Defence is a system in which Black deliberately concedes the centre from the start: castling early, placing the bishop on g7, then counter-attacking with ...e5 and ...f5. White takes space; Black trades it for initiative and a dynamic centre. In the Mar del Plata variation — one of the most theory-dense branches of the opening — Black plays ...Nc6 and then ...Ne7 after White pushes d5, massing pieces on the queenside to prepare ...f5. That is the terrain of games written into textbooks for half a century.

The move the DVD advertises sits in the Bayonet branch: White plays b4, pushing the queenside pawn forward before Black can release ...f5. The main theoretical answer for Black there is ...Nh5, swinging the knight to the rim to prepare ...f5 and ...Nf4, accepting a memory-heavy duel that stays stable if you know the book. The DVD chooses ...a5, a far rarer move, striking directly at the b4 pawn. The phrase "the hour of the seconds" that the marketing material uses for this move sounds impressive, and it hides a simple fact: this is a known, low-frequency sideline, not an invention.

Technically, ...a5 does exactly what the advertising claims. It contests the b4 pawn, forcing White to decide immediately on the queenside — either push b5, or trade on b4 and hand Black the a-file. And it converts the game from forced sequences into manoeuvring, where both sides must judge for themselves. The real value of ...a5 is a reduction in the variance of preparation cost, not an improvement in the quality of the position — and those are two entirely different things merged into one in every advertising sentence. The buyer does not receive a better position; they receive a game with less to memorize. That is a legitimate practical benefit, but it needs to be called by its proper name.

The weakest link in the whole document is the sentence "computers don't understand these positions." That is a claim from an older era. Since neural-network evaluation took over — Stockfish 12 onward, from 2026, along with the maturation of Leela-style engines — closed strategic positions are no longer an engine blind spot in the way the copy implies. The argument that survives is far narrower: in ...a5 positions there are fewer forcing lines to memorize, so the human-versus-engine gap is a memory gap, not an understanding gap. White's analytical team can still engine-check the position in fifteen minutes. "The engine dislikes it" and "the engine cannot check it" are two different things, and the second is false.

There is equally no basis for "objectively the chances are equal." Not one numerical evaluation, not one reference game, not one database citation appears anywhere in the document. In practice the Mar del Plata structure gives White durable space and a queenside majority plan, while Black plays for the initiative. That is a high-variance balance, not a symmetric equality. I have watched enough games in this structure to know the two sides never walk into the same room.

The target buyer is legible enough, even though the document names nobody. For a player below 2026 Elo, ...a5 is useful at a medium-high level, because opponents rarely prepare as far as the Bayonet and strategic guidance beats memorized theory. For the 2026-to-2400 band, this is the sweet spot: opponents do prepare main lines, so a rare move produces the largest surprise dividend. Above 2400, the edge all but evaporates — the opponent and their second already have the move in their files, and ...Nh5 reasserts itself as the mainstream choice.

One variable the document never touches: the half-life of surprise. A rare move is worth something only until the opponent updates. The durability of that gift is inversely proportional to how often the move appears in public events — and nobody measures or states that frequency. The ...a5 move was most likely chosen because it remains underexplored in public databases, an economic decision about what sells as a surprise weapon, rather than a conclusion that it is objectively strongest.

The most telling gap is one of form. A decent opening product normally carries the author's name with a title and a few sample games from a titled player. Here there is nothing: no author, no title, no sample games, no database game count. Even the move sequence breaks — the text jumps from move seven to move nine, skipping ...Nc6 and ...Ne7, without which there is no Bayonet to discuss at all. A writer addressing real players never omits those two moves. And White's three natural replies — b5, Ba3, Nd2 — are the refutation front, yet none is mentioned.

One more practical risk: a strategy-first line is hungrier for thinking time than a memorized forcing line. The buyer of this DVD will suffer more in rapid and blitz, where time is the scarcest resource. A move that sells freedom of thought demands precisely what short time controls refuse to give.

In the age of the thirty-second video, I spent three months listening to a man talk about a game from 2026. The student in Nha Trang does not have three months, and he does not need them. He needs a clear answer to one clear question: is this move better, or merely less to learn? A move is never old; it is only waiting for someone who knows how to listen — and how to ask again.