Puzzle Blog #1 - The Lone Rook

Introduction

Hello good people! For a while, I've been meaning to discuss some concepts that I find helpful in approaching puzzles. At the same time, I encounter fascinating puzzles from time to time in Lichess. Hopefully, this is the first post of a series where I will discuss interesting puzzles and some key concepts.

There are primarily three reasons why I am writing this.

• It will serve as a personal collection of interesting puzzles from Lichess.
• I expect that writing all these concepts will help me apply them more efficiently.
• A contribution to the community where we all can benefit from the discussion.

A fair disclaimer - I am not claiming to be an expert on chess or puzzles. I don't have that qualification. It is more like sharing how I attempt to solve puzzles with the hope that it will be helpful to someone. If there is further discussion eventually, then I am hoping to learn something from you too :)

So without further ado, let's get started!

The Puzzle

I usually listen to music and try solving puzzles before sleeping, it is relaxing and clears my mind. While doing so, I stumbled upon this puzzle a couple of nights ago. I was quite intrigued initially and it felt very satisfying when I managed to solve it after 10 minutes. It took a little luck and a leap of faith. Take a look at the following position. White just moved their rook from b7 to b3, it is black to play and win.

This is a complicated position. But we can follow some simple steps to get a better understanding of the position. Once we do that, it becomes easier to plan for the solution. But before we talk about all these, I urge you to pause here and try it on your own first by clicking on the link above. There is no rush, take your time and try to enjoy :)

A Plan Before Plan

Sightseeing

Let's take a look at each of the pieces on the board. Try to observe their position and count the materials. This might feel like a simple thing, and it is. But at the same time, it is brutally effective and something we should always do when solving a puzzle. While we're at it, as a bonus we can also examine the piece's position and activity. We should do this for all the pieces, including our opponent's.

There is no downside to this but plenty of good things will happen if you do. Even in chess games, sometimes it helps to take a step back and analyze the entire board with a clear mind. Sometimes we can get fixated on certain lines and ideas and that can cloud our vision to see other opportunities.

Inspecting the pieces and the whole board also allows us to get a complete picture of the board and prevents us from rushing to make a move in puzzles. Take your time. Think of it like sightseeing. You are simply enjoying it and there is no need to over-analyze.

Done? That's awesome. We can see that Black has two bishops and a pawn for a rook and a knight, so White has a +1 advantage in terms of material.

Summarize

Next, we will try to summarize our observations. By doing so we can get a concise picture of the board. If we summarize our observations regarding the above position, we get what is listed below.

• Our king is on g5 and it seems scary!
• Our only rook is pinned by the White queen.
• Our dark-squared bishop is trapped awkwardly.
• Our queen seems to be stuck protecting our bishop.
• Our light-squared bishop isn't doing anything useful.
• The White queen seems to be in a very dangerous and active spot.
• The White rooks seem to be positioned nicely and are acting as good defenders of the back-rank and their king.
• The White knight seems to be useless for the time being.

Overall, it does not look very promising for us at first glance. But that's fine. It doesn't always, but often there is something if we look hard enough :)

Threats

It is also important to realize the threats that our opponent has. To do so, we can ask ourselves the question below.

If we could pass our move and if our opponent had the move, what would they play?

We don't always need to calculate all the lines. Sometimes it is enough to consider how only a few selective moves from our opponent could make things difficult for us.

For instance, if it were to be their turn, White can move their rook to c8. Then together with the queen, White could start checking our king and that could pose some serious problems for us. Also, White could develop their most inactive piece - the knight on b1. By doing so perhaps they can also add an extra piece to help in the defense of their king. They also have checks like Qg7+ which could make life tricky for us.

Hence we need to come up with an offensive plan keeping all of these in mind. Note that we must attack in this case since it is a puzzle and we're at a disadvantage. If we don't utilize the tempo, White has a good chance of seizing the initiative and starting an attack themselves. Sometimes, there will be puzzles where we are up material or have a positional advantage and we must make a defensive move to hold on to that. That's not the situation for this particular puzzle, however.

Wrapping Up

Since we have a better understanding of the situation now, we can get to solving it. Given that in this position we are down material, it should be obvious that we need to win some pieces or checkmate White.

Note that for puzzles, one decisive advantage we have is that we know the position is winning for us. In real games, it gets tougher because we don't always know whether our position is winning. Nevertheless, our learnings from puzzles help us to identify and take advantage of a winning position due to pattern recognition.

Analysis

Candidate Moves

It is not always necessary to calculate all the lines in a position. Sometimes, we can look for candidate moves and only consider them. These are the moves that seem likely to hold the advantage. Note that it doesn't have to be the best move. Lichess puzzles have a unique solution and there will always be only one move that holds the advantage. Candidate moves are just a set of possible moves that we will consider as the best move.

You Shall Not Pass The MCQ

Think of it like the choices of an MCQ. There is only one right answer. Even if you can't figure it out, sometimes you can use some tricks to guess it. Imagine that an MCQ has 4 answers. What's 391943 * 6221837?

1. 0
2. 1000001
3. 2438605459291
4. 2438605459292

Notice that you don't always have to calculate it, although if you can that'll work perfectly. It should be quite obvious that the answer won't be choice number 1 or 2, so we can eliminate them. Instead of calculating the entire result, if we observe that the last digit in both the numbers we are multiplying is an odd number. That means their product can't be an even number.

Hence we can rule out choice number 4 too. And once we've ruled out every choice safely except for one, that must be the correct answer, right? In this case, it is choice number 3. We can use similar tricks in puzzles too.

Applying Our Knowledge

In this puzzle, recalling from our observations earlier, we have the following.

• Can't move our rook as it is pinned.
• The dark-squared bishop is trapped, so we can rule it out too.
• Our queen is stuck protecting our dark-squared bishop.
• There are no good pawn moves either.

So if we combine all that we discussed so far, it seems highly likely that our follow-up will have something to do with our light-squared bishop. It is the only piece that can move and isn't doing anything useful.

Moving the bishop back doesn't seem to do much. The only good candidate seems to be Bf3!, with the threat of Qxg2 for checkmate. Also, if White refuses to accept the bishop, there is another hidden threat. Qxh3! Since the g2 pawn is now pinned by the bishop. If we can get there, it'd be dangerous for White because the White king will be trapped, and also under a discovered check from the Black queen when the dark-squared bishop moves.

That's all good, but what if White just takes the bishop? In that case, we can still go ahead and play Qxh3. The White king is trapped and a discovered check is incoming. It is worth noting that the White queen is in a dark square and undefended, so assuming White has no checks for simplicity, they will be left with either preventing mate or losing their queen.

Not So Fast!

However, White is not bound to take that bishop right away. There are some checks available, and White can play one that complicates the position for Black. Note that White can take the bishop first and then go for the check too, it will just be a transposition.

White plays h4+! That pawn was a goner in any case :)

Kxh4 and Kh6 will make the rook fall with tempo, Qxh4 is a draw due to the reasons shown above. If Kg4, then we have the following.

Retreating Ain't So Bad

Hence the correct move is to go back. We play Kg6!

White captures the bishop and we go back to our initial plan. Qh3! Note that if White doesn't capture the bishop, but plays h5+!, it's more or less the same via transposition.

Poison Pawn Check Again

h5+! White offers the poison pawn once more! If Black accepts, then White can go Qxh7+. This leads to the variation shown below and is a draw.

Back, Back, And Back To The Past

How do we respond to White's last move? We can calculate all the lines but there is another trick that we can use in puzzles to avoid calculating sometimes. Let's go back to the previous position when we played Bf3! and White's pawn was on h3.

We wanted White to capture our bishop so that we could move our queen on h3. We know that White played h4+! before capturing our bishop, and later h5+! with a tempo on the king. And they were only played because it was the best move at that position. That's how it works for puzzles, the best response will be played always.

This means we had the advantage at that point, and no other better moves were available for our opponent. And unless having an extra pawn on h5 changed something, we can go back with our king to g5 and still have that advantage. By this logic, if we can make sure that nothing has changed so that our opponent can take advantage of it, we can simply go back with our king to g5 again without considering any other moves! Laziness isn't always bad :)

To Blunder Or Not To Blunder

So we go back to our initial position! The king on g5, the rook pinned by the queen. The difference is that White's pawn is on h5 instead of h3.

White now plays Qg7+!. It seems like we have blundered. Our king has nowhere to go. If Kh4, then White takes the rook with Qxf6+. And if Kxh5, then we get the following.

The Lone Rook

But all is not lost! We have the brilliant counter with Rg6!! The rook cannot be taken by the pawn because of the mate on g2.

White can throw in a few more useless checks, but the result is the same as we can see above. The best move would be to sacrifice the queen for the rook, and we will get the following position at the end of that line.

Black has a queen and a bishop for two rooks and a knight. It can be equal or even better for White, since considering material this means it's almost equal. But in this particular position, Black also has two extra pawns. The piece activity is much better for Black and the White pawns are weak. If the passed pawns of Black starts marching, then it will be difficult for White to contain all of them. Therefore this is easily winning for Black.

Takeaway

• Do not rush.
• Inspect the position.
• Count the materials.
• Observe the position of the pieces and activity.
• Summarize the observations.
• Consider any potential threats.
• Find candidate moves.
• Try to eliminate candidate moves.
• Repeat the process again for the next move.
• Tempo is very important.
• Laziness isn't always bad.

Final Thoughts

Well, there we have it. We're at the end and I hope you enjoyed the puzzle and it was beneficial. Did you solve it any differently? You can also decide to not take the bishop right away, but go h4+, then h5+. Or throw in some queen checks in between, but it transposes into more or less the same thing.

This puzzle is currently rated 2985, and it is not always possible to calculate all the lines unless you have dedication and patience. I've intentionally chosen a difficult puzzle for this exercise. The point is that it is not so difficult if you approach it calmly in an organized manner.

Sometimes, you can calculate smartly and take some calculated risks while making the optimal moves. This can be used to solve even 2700+ puzzles with reasonable accuracy within 5-10 minutes. It could be useful if you have less patience like me, and also might help you find tactical ideas faster in games.

In games, you can assume your position is winning and try to find a winning move like this. However, it's harder because it lasts for many moves and also you don't necessarily know that your position is winning. So you can't always skip calculating a line.

Nevertheless, solving puzzles will build your muscle memory and train your brain to find tactical patterns and motifs. So sometimes you will have your spidey sense tingling that there is something in this position. And if there isn't a winning advantage, then you stick to the basics.

• Develop pieces.
• Improve activity.
• Neutralize your opponent's threats.
• Ensure king safety.
• Control the center.
• Grab space.
• Attack or counter-attack.
• And so on.

That's it for today then, until next time. Cheers!