Miniblog

TLDR;

[…] It is a line suggested by Leelah Zero that was popular around two years ago but fell under the radar[…]. Learning how to play for a win in symmetrical queenless middlegames is very benficial for your chess and endgame skills.

[…]This variation (1. e4 c6 2. Nf3 d5 3. d3) was actually suggested by Leelah Zero 2 years ago and suddenly top players like Ivanchuk, Giri, Nepo, Carlsen and many more started playing it. It is relatively unknown to the general public since it often ends up in technical endgames where you have to accumulate small advantages over time and convert them with accurate moves. This isn't to everybody's taste but is incredibly valuable as it teaches you how to play for a win in symmetrical positions.

The endgame that arises from this variation looks harmless but in fact it isn't that easy. The basic idea is that at some point Black has to move the e-pawn to develop his dark squared bishop which means the d6 square will be permanently weak. This can be exploited by maneuvers like Nfd2-c4 often followed by a4-a5. Carlsen has quite come nice wins in similar symmetrical queenless middlegames and has shown how you can play for a win in seemingly drawish positions[…].

[…]GM Dhopade mentions this line briefly in his promo video on his caro course for Black on the chessbase india channel. Here is the video with the timestamp. https://youtu.be/J5kW8VGAl\_Q?t=3987

Another source that mentions this variation is this video on openings by the chessdojo channel. They mention some deviations and IM Pruess was probably as surprised as you were when seeing this variation but it's a dangerous variation if you work extra hard on your endgame skills. Also there are some quite sharp lines if Black avoids queen trade. Here is the video with the timestamp: https://youtu.be/TE7iY-ilRXM?t=2622

GM Kraai also from ChessDojo channel had a youtube series where he discusses a similar endgame variation but from the Black side with similar ideas as well. The ideas you learn here can be also used for this d3-caro variation: https://youtu.be/qgOPd8q1qIE

Somehow I stumbled upon this variation by chance and I since I wanted to improve my endgames I started playing this variation and I can tell you that the endgame technique on amateur level is not great and if you just make sure you that your endgame skills are a bit better than you can outplay a lot of people from equal positions. It's not about whether the positions are evaluated as equal by the engine. It is about how difficult the positions are in practical play and I think this endgame is more difficult than it seems.

[…]​

Edit: Here is one of the lines GM Perelstyn mentions: 1. e4 c6 2. Nf3 d5 3. d3 Bg4 4. h3 Bh5 5. g4 Bg6 6. h4 dxe4 (6... h6 7. Ne5) 7. h5

Edit 2: I did some googling and I found this repertoire: https://www.modern-chess.com/solid-repertoire-against-the-caro-kann

I cannot say anything about the quality of the analysis […]but from the overview alone you might get some ideas how the positions are play like the Nfd2 idea with the idea of limiting the f6 knight with f3. […]