Video completed: A sharp Slav vol. 1

I recently completed Andrew Martin's "A sharp Slav, vol. 1" 60-minute ChessBase video. This particular Slav Defense variation - responding 3...dxc4 after 1. d4 d5 2. c4 c6 3. Nc3 - I've in fact always played, but was never fully satisfied with the different lines I used previously. Martin focuses on the aggressive 4...b5 response to anything (normally 4.e3 or 4. e4) except 4. a4, which I believe is the correct way to play. Here's the full contents list:

One of the reasons 4...b5 has been demonstrated as preferable is super-GM Hikaru Nakamura's use of it. He in fact is featured in the first model game, which contains an unusual and possibly busted sideline for White (4. e3 followed by 5.a4 b4 and the strange-looking 6. Nce2). The general point of 4...b5 isn't to hold onto the extra c-pawn forever, but to chase the knight on c3 and make White have to work hard to recover the pawn, while Black can play actively and develop. The first game (Mamedyarov-Nakamura) is a great example of this. White in fact had several options to secure a draw, but passed them up and Black won with sharp play (going back to the title of the video).

The essential soundness of this aggressive approach with the queenside pawns is illustrated by the next model game provided, featuring Botvinnik as Black in 1933 (using an older line for Black), as well as the remainder of the lines in all main variations (4.e3, 4.e4 and 4. a4). Martin looks at them in a fair amount of (rapid) detail, while pointing out common themes/ideas, including things like Black's need to watch out for tactical threats from White on the long diagonal after playing ...Qd5. 

There are a lot of similarities between the various lines, whose differences hinge largely on where White chooses to put the Nc3 after it is attacked. White's 4. e4 would seem to be the obvious choice, seizing the center, but unlike with the 4. e3 variations, the Nc3 no longer has e4 available to go to; that is a significant trade-off, as the knight is not very happy either retreating to b1 or a2, having to lose significant time to get back in the game.

Some other commentary on the contents:

• This is not a repertoire for Black (or White), as Martin presents multiple options for variations, and within them as well. He usually signals what he prefers, but he also mentions which ones he considers playable if not preferred.
• Martin presents each game somewhat quicker than normal, I would say, which I expect is due to the limited total time format. I found myself going back several times in each individual video to review particular lines, rather than being able to keep up in real time, but that's not a terrible thing necessarily.
• It's very helpful to see the full games in each case. This is not an opening theory product, rather one that's intended for training, familiarization and understanding. In addition, this is not an opening where either side is going for an early knockout blow, so it's important to see how the middlegame (and sometimes endgame) can flow from the opening.
• Favorite quote: "4. a4 might be played by cowardly opponents who do not want to brave the complications after ...b5."