[April 2, 2019] Announcement of the Discontinuation of Service

Dear users and chess friends,

We are sorry to inform you that, starting from April 2, 2019, Chess Openings 24/7 Encyclopedia (CHOPIN) and articles (Pick of the Week and Opening Surveys) will no longer be updated. The service will remain online until July 1, 2019, after which it will be discontinued completely.

CO 24/7 has made every effort to work out a sustainable business model over the past few years, but we still failed to succeed. Due to the nature of our contract with our e-commerce provider and their bank, we can only refund user payments made in March 2019 (all subscriptions will remain active until the final discontinuation of service).

We deeply apologize for the inconvenience caused – our sincere wish has always been to make a meaningful contribution to the chess community, and we have been putting our money into the project for a very long time, but we can no longer do that.

Hoping that you will understand the circumstances that led to this unfortunate outcome, we remain

Sincerely yours,

Chess Openings 24/7 Team



[March 18 – April 1, 2019] Springtime Break

Dear users and chess friends,

Springtime break is about to begin for the members of Chess Openings 24/7 Editorial Board. Our team will be enjoying a well-deserved break between March 18, 2019 and April 1, 2019, so we will not publish new content during that period.

For those celebrating it – Happy Saint Patrick’s Day!


[March 17, 2019] Updated Opening Article by Boris Avrukh:
April 2015 Revisited: Semi-Slav: Stoltz Variation, Main Line (12. Ng5 c5)

Our original key game of this line was played in the third round of the 2015 US Championships in Saint Louis. Wesley So had initially managed to surprise Sevian in one of the most complicated Semi-Slav lines, but failed to proceed accordingly, and his position eventually collapsed.

This is a theoretically important line, which got worldwide recognition in 2013 after Anand’s brilliant disposal of Aronian in Wijk aan Zee, so revisiting it is the most natural thing to do, given the circumstances. Fortunately for us, in the meantime a number of over-the-board, correspondence and engine games took place, which gave us the opportunity to examine this variation more deeply.

[Diagram: Black to Move] The diagrammed position is from an extremely important correspondence game A. Steenlandt – R. Ramesh, corr. 2015. How can Black proceed with his attack and break White’s defense?

Click here to see the updated article in our viewer.


[March 16, 2019] Updated Opening Line by Trajko Nedev:
Sicilian Defense, Najdorf Variation (Miscellaneous)

[Line 477 : 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 without 6. Be3, 6. Bg5, 6. Be2, 6. Bc4, 6. f3, 6. f4, 6. g3]

Various choices of White on 6th move can be found pretty much everywhere in our CHOPIN Encyclopedia: 6. Be3 in Lines 491-500, 6. Be2 in Lines 484-490, 6. Bg5 in Lines 481-483, 6. Bc4 in Line 480, 6. f4 in Line 479, and 6. f3 and 6. g3 in Line 478.

The main topic of Line 477 is 6. h3, a move that has become exceedingly popular among the top players in the recent years. White’s plan includes g2-g4, Bg2 and Be3, hoping to exert pressure on the kingside. Black has tried numerous options in response, but only 6… e6 and 6… e5 seem to be sufficient for getting equal chances. There are many possibilities for both sides, and we will mention here the two currently most popular lines: 6… e6 7. g4 Be7 8. Bg2 Nfd7 9. Be3 Nc6 and 6… e5 7. Nde2 h5. In both cases the ensuing positions are highly complex and, though Black should be the more cautious side, he should typically be able to equalize.

From the other options for White, the following stand out: the classical 6. a4, somewhat unusual 6. Qf3 and 6. Rg1, the hypermodern 6. Nb3 and even 6. h4.

[Diagram: White to Move] K. Sasikiran – Lu Shanglei, Abu Dhabi 2016. Black is threatening to take the b2-pawn, though he would also be quite happy to play Ne3, eliminating the opponent’s important dark-squared Bishop. Sasikiran played a very strong move that allowed him to gain a substantial advantage. Can you find the best continuation for White?

Click here to see the line in our viewer…


[March 15, 2019] Updated Opening Line by Bojan Vučković:
Queen’s Gambit Declined, Alatortsev Variation & Schara-Hennig

[Line 061 : 1. d4 d5 2. c4 e6 without 3. Nf3]

After the introductory two moves shown above, two most natural third moves for White are 3. Nf3, covered in Line 063 and 3. Nc3, which is the topic of this opening line.

After 3. Nc3 Black usually choses between Alatortsev Variation (3… Be7), classical Queen’s Gambit Declined with 3… Nf6 (Line 171), the so-called Triangle Setup 3… c6 (Line 067) or even 3… Bb4. There are also a few sidelines that are occasionally seen on grandmaster level: the solid 3… a6, risky Schara-Hennig Gambit (3… c5 4. cxd5 cxd4) or, a not very promising line for Black with 3… dxc4.

Against the Alatortsev Variation, apart from a transposition to Line 253 with 4. Nf3 Nf6, and the common 4. cxd5 exd5 5. Bf4, White can also opt for immediate 4. Bf4, followed by 4… Nf6 5. e3 O-O 6. a3, with the idea Nb5.

The most frequent choice after 3… Be7 4. cxd5 exd5 5. Bf4 is 5… c6, covered in our Line 062, but Black has another option – 5… Nf6. After 6. e3 Black again has two notable possibilities: 6… Bf5 and 6… O-O

[Diagram: White to Move] White pieces are aiming at Black King. What is the best way for White to proceed with the attack?

Click here to see the line in our viewer…


[March 14, 2019] Updated Opening Line by GM Borki Predojević:
Queen’s Gambit Declined, Harrwitz Attack

[Line 253 : 1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. Nc3 Be7 without 5. Bg5]

The Harrwitz Attack, characterized by the topical 5. Bf4 is, besides 5. Bg5, one of the two most popular systems against the Queen’s Gambit Declined. It’s a frequent guest among the elite so, due to sheer quantity of the information, the remainder of the material is covered in Lines 254-257.

The Fianchetto Variation with 5. g3 has recently gained in popularity, mostly due to Kramnik’s incredible input of original ideas for both sides, like in recent P. Svidler – V. Kramnik, Skopje 2015 and V. Kramnik – V. Topalov, Tromsø (ol) 2014.

We especially recommend that you take a closer look at an incredibly spectacular game P. Svidler – A. Morozevich, Sochi 2012.

[Diagram: White to Move] The diagrammed position is well-known from many games, ranging from classical B. Ivkov – K. Robatsch, Vinkovci 1968, to some recent correspondence and engine games. After energetic play, White gets a strong attack!

Click here to see the line in our viewer…