Tactics Analysis #2

Current Puzzle rating: 2224 (+74)
Current puzzles completed: 945 (+49)

In these posts, I analyse some tactics positions from this week that I struggled with or found difficult to understand, in order to better understand the positions and ideas.

Position #1

Black to move
https://lichess.org/training/OEF0y

I made the same mistake with this position when I was analysing it for this post and when I first played it. I saw the idea Black has to attack for mate, but missed the best move after White defends with the knight.

SOLUTION

1. ... Bxg2 (threatening Qh3) 2. Ng1 Bxc6

Position #2

Black to move
https://lichess.org/training/5m42S

In this position, Black finds himself in check but with a potential one-move mate and also trying to promote his advanced a-pawn while trying not to be overwhelmed in the centre. Black has four legal moves - Qf6, Rg7, Qg7 and Qxe5.

Rg7 loses immediately to 2. Rf8# so we'll discount that and the obviously-bad Qf6 right away.

Qg7 leaves the choice up to White, to trade queens or not to trade, which makes this unlikely to be the answer to a tactics puzzle. I think White will choose to trade queens to play a line like Qg7 Qxg7 Rxg7 (or Kxg7, I don't think it matters) Ra1 and Black will lose his a-pawn and can expect to be overwhelmed (can he hold after Rc8 c5? I doubt it). Being less meta-analytical, because in a real game we wouldn't know there's a tactic here, allowing White to make the decision wastes a tempo, as we will see from the solution.

1. ... Qxe5 2. dxe5 is our last move to analyse, so what does Black do next? I had a similar idea in a couple of recent blitz games (I play blitz on the... other... site, to keep my ratings separate, because I'm weird) and actually found it, so I was annoyed not to find the answer here.

SOLUTION

1. ... Qxe5 2. dxe5 Rb8 3. e6 Rb1 (if 4. Rxb1 axb1=Q+; if 4. e7 Rxf1+ 5. Kxf1 a1=Q+)

Position #4

https://lichess.org/training/tlod9

It's clear Black has only one winning plan - to force through one of the pawns on the kingside. He also must not allow the knight to take up residence on a light square as this will be impossible to dislodge. There's really only one first move to consider - 1. ... f3

After this, White has a few options. I briefly looked at c5+ but the bishop will just take it and if the knight takes the bishop Black pushes his f-pawn. We might consider gxf3 but this clears the way for g2-g1=Q. So White must move the knight, and most options make no sense (Nc1, Ne1, Nb4, Nc5 - all nonsense). Nf4 is the only thing that looks sensible. Now Black obviously cannot play fxg2 as the knight will take, so he must dislodge the knight with Be3 and White protects with Ke4.

Here is where I went wrong. I thought f2 now the way is clear and the pawn promotes, but White has a fantastic saving move - Nd5+! After the Black king moves, White takes the bishop and now guards the queening square f1 (Black can't take the pawn on c4 even if it becomes unguarded as the king will be too far from the b-pawn). Instead Black must give up on the f-pawn and use the last piece on the board instead.

SOLUTION

1. ... f3 2. Nf4 Be3 3. Ke4 Bxf4