Owen's Defence (also known as the Queen's Fianchetto Defence[1]) is an uncommon chess opening defined by the moves: By playing 1...b6, Black prepares to fianchetto the queen's bishop where it will participate in the battle for the centre.
The downside of this plan is that White can occupy the centre with pawns and gain a spatial advantage.
[3][4][5] Owen's Defence is classified as code B00 by the Encyclopaedia of Chess Openings.
Owen seems to have used 1.e4 b6 as his main defence for the majority of his career, including in two games against Paul Morphy in 1858 (scoring one win[7] and one loss.
[8]) In 1889, Owen's Defence was played seven times by Isidor Gunsberg at the US Chess Congress (scoring +4,=2,-1), but the opening was otherwise a very rare visitor in master level chess until the 1970s when it was adopted by freethinkers such as Bent Larsen and Michael Basman.
In more recent times Owen's Defence has been played with some regularity by grandmasters Pavel Blatny, Artashes Minasian, Nona Gaprindashvili, Tony Miles, Edvīns Ķeņģis, and Normunds Miezis, and by International Masters Bauer, Bricard and Filipovic.
[9] The opening remains rare but has enjoyed a certain amount of popularity in top-level online blitz tournaments, including in games by Alireza Firouzja, Magnus Carlsen, Hikaru Nakamura, Ian Nepomniachtchi and Teimour Radjabov.
[2] GM Christian Bauer observes:[10] To be honest, I don't think Black can equalise as quickly with 1...b6 as he sometimes does in standard openings, and he may suffer against a well-prepared opponent.
Then again, the well-prepared opponent is rare for such marginal variations as 1...b6, and in any case, with reasonable play I'm sure White can't get more than a slight advantage from the opening – a risk everyone is running as Black, aren't they?After 1.e4 b6 2.d4 Bb7 the mainline has historically been 3.Bd3 e6 4.Nf3 (4.c4 would transpose to the English Defence) c5 5.c3 (see diagram), after which MCO-15[11] gives clear advantage to White after either: 5…Nf6 6.Nbd2 Nc6 7.a3!
GM John Shaw has suggested that White may fare even better by opting for 5.Nc3[12] after which Black has little option but to play ...cxd4 (either immediately or in the next few moves) transposing into an unorthodox type of Open Sicilian where Black has played an early ...b6/...Bb7.
According to IM Lawrence Trent, 4…c5 has ‘generally been almost refuted by cloud engines’.
Possibilities offered by Trent include 5.e5 Ba6, which gives an Advance French type structure where Black can swiftly exchange off his bad bishop, and 5.exd Qxd 6.Nc3 Qd8 where the structure might be taken to resemble either an unusual form of Qd8 Scandinavian or a rare type of Exchange French where Black had re-captured with the Queen to keep the pawn structure asymmetrical (i.e. 1.e4 e6 2.d4 d5 3.e4xd5 Qxd5!?).
German opening theoretician FM Klaus Gewehns[14] considered much of the complex after 3.Bd3 e6 to be dangerous for Black and instead concentrated on 3...Nf6 (as often played by Owen's Defence specialist Pavel Blatny), the most frequently played continuation here is 4.Qe2 e6 5.Nf3 d5 6.e5 Nfd7 7.0-0 c5 (see diagram), another French-type handling of the opening.
It had been developed and played by the Slovakian International Master Maximilian Ujtelky a few years before this.
[25] This opening was invented by a Guatemalan named Roberto Asturias, and further investigated by his compatriots including David Vela [es] and Hans Cohn [de].