Caro-Kann防禦：終局邀約及Dinic棄兵

不知什麼因緣際會，再度接觸到Caro-Kann防禦的「終局邀約^*」變例。讀到下方的一則Reddit留言，發現這是Leela Zero在2020年開始帶來的風潮^*。白方3.d3，在開局階段就「邀請」黑方兌兵兌后，直接進入終局。看似平淡的終局，在最高等級的棋局，却讓白方享有極高的勝率^*。該留言還指出學習如何贏下這個終局應能受益匪淺。

u/tartochehir/chessBen says the Caro-Kann is dead

2022年1月10日下午6:51

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. […]

在Lichess研究此變例時，一旁摘自Wikibooks的講解提到白方除了兌兵還可以像Tennison棄兵一樣走4. Ng5，即Dinic棄兵。這個棄兵具備著Tennison棄兵相似的性質，或許還比它更具威脅性：5. Bxd3 後同時威脅著Nxh7 和Nxf7 ^*，而據Lichess統計^*，黑方約有80%都走錯了。

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希望此後可以在我的開局錄^*代替較魯莽的外星人與火星人棄兵^*。

無論如何，可以確定的是應對Caro-Kann防禦的棄兵中心思想是Nxf7 ^*。