King's Indian: When 9...a5 Is Sold as an "Antidote" to the Bayonet Attack

In my personal spreadsheet, the column tracking White's ninth move keeps growing thicker with every season. 9.b4 — the Bayonet Attack — is not a new move, but its frequency in club and semi-professional games has risen steadily over the past three years. That is why, when a new opening product appeared claiming to offer a "clear antidote" to the Bayonet Attack, I did not rush to believe it. I reopened the data, placed the familiar 9...Nh5 and the newly marketed 9...a5 side by side, and asked myself: what here is genuine strategy, and what is merely a salesman's phrasing? Everything on the board is data waiting to be read — if you are willing to sit down. The King's Indian Defense is an opening in which Black voluntarily concedes the centre. After 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 0-0 6.Be2 e5, White has space and Black has structure. The Mar del Plata variation arises when Black plays 7...Nc6, accepting White's 8.d5 Ne7 and opening a position where both sides gamble on opposite wings. It is one of the sharpest systems in modern chess: Black usually attacks the kingside, while White floods the queenside. White's 9.b4 is the bayonet. White does not wait, immediately pushing the pawn to threaten b5, drive away the knight and open files on the queenside. Black usually answers with 9...Nh5, sending the knight into the kingside attack and accepting that the game will become extremely complex, dense with forced lines, where computer analysis plays a decisive role. The product now being promoted chooses a different path: 9...a5. Black does not charge at the kingside, but strikes directly at the b4-pawn, reclaiming control of the queenside. The promotional copy describes this as "sound", "equal", "few concrete lines", and stresses that the focus is strategy, not tactics. First, one thing the marketing does not say: 9...a5 is not an invention. It is a sideline known for a long time, historically used to strike directly at the b4-pawn and White's queenside. It is not a new move, but an old choice repackaged. That does not make it worthless, but it changes how the pitch should be read: this is a relative antidote, not a theoretical overthrow. Technically, 9...a5 and 9...Nh5 represent two philosophies. 9...Nh5 opens the game, the lines become forced, and — as the author himself concedes — computer analysis becomes important again. 9...a5 keeps the game strategic, with fewer forced lines, demanding that the player understand long-term plans rather than memorise move sequences. That is the real selling point, and it is reasonable. For a club player with no time to cram hundreds of variations, a low-theory sideline like 9...a5 has obvious appeal. You do not need to remember precisely to move thirty; you need to understand that you are hitting the b4-pawn, that the queenside is the battlefield, and that you must balance counterplay with kingside defence. But here the data falls silent. There is not a single number in the introduction: no win rate, no draw rate, no sample of games, no engine match rate, no average centipawn loss. Every adjective — "sound", "equal", "few concrete lines" — comes from the seller. Based on my experience following games, that is the first sign to lower expectations. And one claim I particularly distrust: that computers "do not know how to handle" these positions. That is almost certainly marketing language. Modern engines handle King's Indian Mar del Plata positions very well. The author himself, elsewhere, concedes that after 9...Nh5 computer analysis "becomes important again" — meaning engines do evaluate these structures. The two statements contradict each other. The King's Indian does not create strategy; it merely unmasks those pretending to understand it. The real risk lies not in the move, but in the player. Because 9...a5 demands strategic understanding, its reward is locked behind whether the buyer actually absorbs the plans. The author admits: if Black knows what to do, the position can quickly become dangerous for White. But if Black does not know, the very comfort of "not needing to memorise" becomes a weakness. A sideline with few forced lines means fewer prepared traps, but also less margin of safety if you misjudge the plan. There is one more factor: time control. Slow strategic plans are often punished in rapid and blitz. There, the forced lines of 9...Nh5 — however theory-heavy — enjoy the advantage of clarity. This is the paradox: the "comfortable" sideline requires more thinking time. There is another, more counterintuitive reading. Dividing the world into "strategic players" and "variation grinders" may simply be market segmentation. In chess, no line is purely strategic or purely tactical. 9...a5 still has its own forced lines, just fewer. 9...Nh5 still demands structural understanding, its forced lines merely denser. The boundary is relative, and every salesman needs a boundary to draw difference. More notable is the cyclical nature. The practical value of 9...a5 depends on how popular the Bayonet is. When White plays 9.b4 often, the sideline has surprise value. When the Bayonet fades, so does its appeal. So this is not a permanent tool but a weapon with an expiry date — and the buyer should know that the expiry date is not his to decide. I no longer believe in miracles on the board; I believe only in the conversion rate of an advantage. And then I realised: this story is not only about chess. In football, people once sold "the perfect pressing system" and "the anti-counterattack formula". What sells is always clarity; what wins is always understanding. With 9...a5, I do not ask whether it "solves" the Bayonet. I ask only whether it is worth the time to learn. And the answer, as always, lies in the data — which the seller has not yet provided.