9...a5: An Antidote to the Bayonet Attack, or Old Theory in New Packaging?

9...a5: An Antidote to the Bayonet Attack, or Old Theory in New Packaging? Hook White's ninth move lands on the board in a second. 9.b4. In the King's Indian Defense, inside the Mar del Plata structure, this Bayonet Attack is a long-standing headache for Black — an accounting move that blocks Black's natural queenside plans, sealing off the usual ...b5 break before it can be played. In my hands was a promotional DVD whose single commercial promise ran: against the Bayonet, play 9...a5 and free yourself from the tangle of computer lines. I read the promo copy twice. It said that in this line chances are objectively equal — yet that if Black knows the plans, things can quickly become dangerous for White. Put the two sentences together and you get a strange claim: a comfortable path that is somehow better for Black than for White. In three decades of chess reporting I have heard such promises many times. But this time there was a specific number in my hand — move nine. The notebook says one thing; the tape says another. This piece sets the two side by side and tries to balance the ledger. Context The King's Indian Defense is a hypermodern defense: 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7. Black deliberately concedes central space to White, then strikes at the center with ...e5. When 7...Nc6 arrives in the Classical branch, the Mar del Plata Variation is born — both sides attacking on opposite wings: White on the kingside, Black on the queenside. It is one of chess's oldest duels, two players almost playing separate games on one board. In this structure, White's sharpest weapon became 9.b4, the Bayonet Attack. It rose to popularity in the 1990s because it breaks the rhythm of Black's queenside expansion and gives White room to occupy c5. Black's traditional reply became 9...Nh5, the knight heading to the rim to eye f4, opening the position into sharp, forcing play. By the Bayonet era this main line had been analyzed so deeply that, in the engine age, playing it is almost a battle of memory — a contest of who errs less. That is exactly the DVD's marketing logic. The main line 9...Nh5 is so thoroughly analyzed that for a club-level Black player it is an unequal fight: the opponent may be sitting on engine memory while you are thinking at the board. So the DVD says: leave the main line, choose 9...a5. The only question now: what is this alternative really, and what does it cost? Core Analysis The move 9...a5 looks harmless. But its inner logic is clear: Black wants space on the queenside, wants to press ...a4 to weaken White's b4 pawn, and wants to prepare the ...b5 break later. Since White played the Bayonet 9.b4, Black's natural ...b5 break is already blocked by that very pawn; 9...a5 prepares the break slowly, from a lower floor. This is the fundamental difference from the main line 9...Nh5 — where the game opens at once, here the game stays closed and rests on plans. Here is the DVD's strongest sentence: this line has very few concrete lines, so the player can think for himself. For a chess player this is an appealing offer — because in the age of memorized lines the space for think-for-yourself players has shrunk. In my experience on the club and tournament circuits of Bangladesh and India, there are many players who lose in memorized lines but win in genuine battles of ideas; for them this kind of sideline means a chance to use their own strength. But here is the first gap. The DVD claims the line is roughly equal. To prove equality you need engine evaluation, database statistics, sample games. None is provided. 9...a5 is not a new move — it is a known, old sideline in the King's Indian. In the Bayonet era its core idea is queenside space around ...a4 and ...b5, and avoiding the forcing ...Nh5 lines. In other words, the DVD is not giving new theory; it is re-packaging old theory. That is no crime — it is a business model. The second gap is subtler. The DVD claims computers often do not understand these complex strategic positions. In the modern engine age that sentence is almost anachronistic — it speaks of an older era. Today's engines evaluate the King's Indian's closed, strategic positions very well, because they can assess space at great depth. What computers cannot really do here is make human-like aggressive errors. So the sentence is weak as a technical claim; it is a marketing template. The third gap is the largest: reliance on a single sideline. The practical claim is true — less memory, more understanding. But once the opponent knows you play 9...a5, White will tailor the preparation, and your surprise advantage evaporates. In my ledger, reliance on one line means a large risk to future forecasts. The best repertoire never rests on a single move; it holds alternatives. So where is the DVD's real use? In my view, not in the move 9...a5, but in a lesson. The trade-off between main line and practical sideline is made clear here: memorized, forcing play versus slow, strategic, understanding-based play. For club-to-IM level players who lose time in forced main-line preparation, this trade-off is valuable. But to treat it as an upgrade for elite GMs is a mistake — there the main line remains the standard. My notebook says another thing. When an opening becomes so analyzed that sidelines begin to be re-marketed, that is proof of the opening's maturity — and also proof that the content market now turns sidelines into products. Just as the Bayonet's rise in the 1990s ran through books and databases, now the era of sidelines arrives through streaming courses and DVDs. The technology has changed; the marketing template is the same. A larger question arises: is such a sideline really a solution to Black's problem, or is it a mental comfort of dodging the main line? In chess history I have seen that if White knows how to play his main weapon well, any Black sideline only changes the path of the suffering, not the amount. 9...a5 frees Black from the cramping computer line, but does not give central control, does not give a balance of space. The game becomes easier, but not better. Contrarian Angle The most unexpected aspect of this report is not technical but evidentiary. The article's title says ChessMom has returned, about standing beside mothers on and off the board. But every piece of content inside concerns one thing — a 9...a5 repertoire against the Bayonet Attack. That gap between title and content is itself a signal: the product's marketing and its actual content come from two different places. The emotional message about mothers' involvement seems bolted onto a purely technical product. Combined with weak evidence, this mismatch raises a warning — until the product's true identity and authorship are confirmed, its claims should not be trusted. The second unexpected aspect: the DVD's strongest sentence — computers do not understand these positions — works in the opposite direction. In the engine age the demand for sidelines grew because of computers, not despite them. Because the engine drove the main line so deep, club players now flee to sidelines to survive. In other words, the computer is not the enemy here; the computer is the parent of this market. What the DVD sells as computer incapacity is actually the result of computer influence. The third unexpected aspect — and this I will stress — is that the real value of such a product is not in the move but in the method of choosing moves. If a player learns how to weigh the trade-off between main line and practical line, he benefits in any opening. The DVD's most valuable part is therefore not 9...a5; it is that lesson — how to spot the memory trap and choose your own ground of understanding. Selling a sideline is easy; teaching is hard — the decision process behind the sideline should have been the real product. And finally, the commercial reality. The DVD is an old delivery medium. Today's content market has moved to streaming and subscription — Chessable, Chess.com courses, YouTube. This DVD therefore looks like a catalog re-release rather than new theory. For the buyer the meaning is simple: before spending money, verify the line yourself on free databases and an engine. Takeaway So the ledger reads: 9...a5 is a valid, known sideline that seeks to dodge the computer-cramped line — but its equality claim is unproven, and the computers-don't-understand claim is era-blind. It is not elite theory, but a practical club-level tool. What to watch next: whether this sideline finds a place in elite practice, and whether White can show a clear edge against it. As long as White lacks a strong answer, the line will hold — but trusting one line means leaving your repertoire half open. And that is chess's oldest accounting: bigger than any product, the depth of your own preparation.