Tactics Analysis #15

Current Puzzle Rating: 2304 (-13)
Current Puzzles Completed: 2900 (+100)

I did briefly set my highest puzzle rating this week (was 2352 at the end of one day, think I was briefly 2370 at one point). I feel like I've seen some improvement in my game, and had a few good puzzle solves. I'm not putting too much importance on this rating but it's always nice to do well and feel good.

That said, there are of course many problems that I failed, either because I didn't get the idea or I couldn't work it out, so we'll take a look at some of those.

Position #1
https://lichess.org/training/LbIeR

I had some difficulty finding the follow-up to the check 1. Qh6+, which was my main idea. I saw Kf7 Qf6+ won the bishop, but I couldn't see how to respond to 1. ... Rg7. It turns out to be a fairly simple move, and one of the keys to it is recognising that we need to defend against Rg2+ ideas (which is why we can't follow up by taking the bishop).

SOLUTION

1. Qh6+ Rg7 2. Bf6 (pinning the rook)

Position #2

https://lichess.org/training/9UitM

I looked at the best move in this position but wasn't convinced it was good. Instead I tried Qg3 intending 1. ... Qg3 2. Rg2 Qe1 !!!, so now I feel really good about the bit at the start of the blog where I said how high my rating had been.

The best move is 1. ... e2. I expected the defence 2. Qxe2 and assumed I would play Qxe2 in response which is clearly bad for me. However the right king is very restricted, which leads to a much better second move for Black (2. ... Be3)

SOLUTION
1. ... e2 2. Qxf3 Kxf3 3. Rh3+ Kg4

Position #3
https://lichess.org/training/0ik8b

I found this one very difficult even playing it through multiple times, so I'm going to play it out and work through the moves, rather than presenting it as a puzzle.

1. exf6 - taking the free bishop and threatening the queen
1. ... Qh7 - Rxe4 2. Bxc7 is a bad trade. Anywhere other than Qh7 is vulnerable to Rg4+ leading to mate (except Qb6, where 2. c5 has all the same problems - either trade the rook for the queen, or lose the game)
2. f7+ - only has three legal responses, two of which have the same problem. Either king move leads to an exchange of queens and then the exchange on f8 (e.g. Kg7 Qxh7 Nxh7 Rxe8 Rxe8 gxe8=Q, or similar variations). Black has Qxf7 as the third option - it's the best one so we'll play it
2. ... Qxf7 3. Rg4+ - Black can block with the knight if he wants to lose faster, but eventually he'll have to block with the queen and it will be taken - 3. ... Qg7 4. Rxg7 (4. Be5 might be very slightly better but Rxg7 is good enough)

Position #4
https://lichess.org/training/saYqH

A nice little knight endgame sequence. Two obvious features - our h5 pawn is gone, and we want to promote on d1 (which means the White knight can't move except to d1, or to give check). We can use these features to decide what we need to do (force the knight away) but actually calculating how to do it is slightly different.

One fact I found useful to help me work this out is that knights need to make three moves to check when the king is two squares away diagonally (so if we play Kd4 above, the White knight needs to play something like Nd1-Ne3-Nc2+)

The official version of the puzzle ends after 2 moves, but I think we need to find the ideas on the next two moves to really have this in hand.

SOLUTION
1. ... Kd4 2. Kxh5 Kc3 3. Nd1+ Kc2 4. Ne3+ Kc1 (controlling the promotion square and establishing the king two squares away diagonally 5. Kg5 (various other moves are roughly the same) Nc2 (the knight either leaves and lets us promote, or gets exchanged and we promote anyway)