Mar del Plata and the 9...a5 Promise: An Antidote to the Bayonet Attack, or a Data Gap?

“I trust footage more than testimony, because footage does not lie.” In the editing room, I rewound a King’s Indian game frame by frame. After White’s 9.b4 — the Bayonet Attack that players still liken to a drill biting into the queenside — Black was supposed to touch the kingside, push the knight to h5, open the position, and force the opponent into a chain of compulsory moves. The game in front of me did none of that. Black pushed a pawn to a5.

An old move. But the way it is being packaged is new. Around 9...a5, someone is selling an opening DVD with a loud promise: this is an antidote to the Bayonet Attack, turning one of the sharpest lines of the King’s Indian into a strategic game with little to memorize. It sounds like relief for players tired of memorization. But rewinding footage is about finding numbers, and the numbers here are missing.

The King’s Indian Defense is the school of patient players. Black accepts that White will build a center, then strikes back at that very center — an idea both Fischer and Kasparov once used as a weapon. In the Classical system, the Mar del Plata is the sharpest version: Black puts the knight on c6, pushes the e-pawn to the fifth rank, and turns the game into a race of mutual wing attacks. White throws everything at the queenside, Black at the kingside, and whoever arrives first wins.

The Bayonet Attack came as White’s answer: 9.b4. Instead of playing slowly, White grabs queenside space at once, clears the way for the pawns, and threatens to open the wing before Black finishes the assault. Black’s conventional reply is 9...Nh5 — pushing the knight to the rim, opening the position, forcing both sides down pre-set paths. That compulsory character is exactly why 9...Nh5 became the main line: it gives Black a clear position, but also drags the game into the zone where the strongest analytical tools reign.

The Bayonet Attack is no novelty. It rose in the 1990s, when leading players looked for ways around the long theoretical lines of the traditional Mar del Plata. 9.b4 confronts Black with a hard choice: either dive into the main line 9...Nh5 with every move memorized up to move thirty, or accept a different position that popular literature covers less. That documentary gap is fertile ground for opening products.

The DVD takes the other road. Its marketing says 9...a5 leads to sound positions with very few concrete lines, suited to players who want to think for themselves rather than memorize. The product targets a specific audience: club players tired of memorizing every branch of the Bayonet.

In positional terms, the difference between the two replies is a difference in the nature of the game. 9...Nh5 opens the kingside, brings pieces into play, and turns the game into a race where every move can be measured by the clock. 9...a5 keeps the kingside shut, puts a question mark on the b4-pawn, and invites a maneuvering game where plans matter more than memory. To club players, the second option sounds far more comfortable. To professionals, that same option is a dangerous invitation.

The first thing I check when I hear an opening promise is data. This time, the promotional material carries not a single figure. No win rate, no draw rate, no ACPL, no sample game cited. Few concrete lines is an adjective, not a measurement. For someone who makes documentaries, an unverified claim stays unverified until a sample proves it.

The point worth noting lies not in 9...a5 itself, but in the distance between what is promised and what is proven. 9...a5 is a known sideline, not an invention, and its value depends on White being underprepared. Sidelines survive for exactly that reason. Once 9...a5 appears often enough, professional White players will sit down, take it apart, and almost certainly find a way to keep a small edge. That is the rule of the field: no line stays outside the analytical loop forever.

The argument that stopped me longest concerns computers. The marketing says positions after 9...a5 belong to a class engines often struggle with, so they demand human calculation. That claim has a time problem. It reflects the thinking of the old engine generation, when tools were dominated by brute-force search. In the neural-network era, long-term King’s Indian positions are handled far better than the sentence implies. Hanging a product on the flaws of yesterday’s computers is selling past its expiry date.

So I turn the skepticism on myself. Having demanded data from the seller, I owe data on my own doubt. In truth, the view that 9...a5 can give Black equality is not wrong. It is simply unproven. Theoretically, Black can reach a stable, playable position, as long as White does not punish it at the board. That is where the DVD’s value sits — practical utility for a certain group of players, not absolute correctness.

The real question is not the move but the level of the promise. The same 9...a5, if advertised as a sideline worth trying, a possible surprise weapon, would be an honest product. When it asserts that if Black knows what to do, things quickly become dangerous for White, that is exaggeration. Professional White players have more resources and more time to refute it than any advertisement can match.

There is one further matter, belonging to sourcing rather than to the move. The document is betrayed by its own frame: the headline talks about a team event in Samarkand, while the body talks about an opening DVD. The two have nothing to do with each other. I once rewound footage to find what others left out — but rewinding footage also means noticing when a reel has been spliced wrong. Here, the reel is spliced wrong, and that forces every technical claim inside it to be suspended.

Every documentary is a track: the audience sees the finish line, I live at every starting block. With 9...a5 it is the same. Viewers see a move and a promise. I see the gap between the two. This sideline may well be worth trying, and chess players have every right to test it in their club games. But it is not insurance. The opening market thrives by selling a feeling of safety, and the shrewdest buyer is the one who verifies it on their own board, not through an advertisement.