In previous posts I discussed the process of calculating forced variations, which begins by first finding all threats. After every move your opponent makes, stop and look for ALL threats your opponent has created. If you find one, keep looking for more. For example in the below position, how many threats did white's move Qe4 create?
White has two threats: the mate threat (Qxh7) and the capture on d4 (Qxd4). The mate threat takes priority, but ideally black would like to find a move that prevents mate while also defending his bishop. In subsequent posts we'll go through the calculation process to find black's best response. For now though let's just focus on identifying and prioritizing the threats.
Some positions are more complicated, such as the following:
White has two threats -- to mate on f8 (Rxf8), and to play Qe5 creating two new threats for a total of three: to capture the queen (Qxc5), to mate on g7 (Qxg7#), and to mate on f8 (Rxf8) if the queen moves. The mate threats are greater than the threat to the queen. Here it does not matter whose turn it is to move and we're not calculating defenses yet. We're just looking for all the threats we can find.
It is also very important when you are assessing the threats that you take time to make sure it is a real threat. To do that you need to calculate a bit. The trick I recommend is to skip your turn, and allow the "threat" to play out in your mind. At the end of the line you can ask yourself what you could do with an extra move (the one you skipped).
Take this postion for instance. White just played Nf3. Find and prioritize white's threats:
One might look at this position and see white's "threat" to play Nxe5, winning a pawn. But before we start calculating how to deal with that "threat", let's skip our move and visualize the position after Nxe5. Is it any good? Has white just won a pawn? Are we just sacrificing our pawn for some sort of initiative? Anyone who has studied some tactics should quickly find that black has the immediate queen fork (Qa5+) hitting the king and the now loose knight on e5. There is no way to deal with the check and defend the knight at the same time, so black wins a knight for a pawn. Therefore, black does not/not need to address the threat to e5, and can go on with any regular move that doesn't block his queen fork, such as 0-0.
You could also say that the pawn on e5 is tactically defended, but in order to see that you have to allow the "threat" to play out in your mind (unless you already know the pattern, or the specific opening in this case...that all comes through training and experience).
Keep in mind both of these steps as you play: (1) find and prioritize all threats, and then (2) make sure the threats are REAL!! Cecil Purdy calls this "recognizing the unreality of their unreal threats".
IM Andrew Martin has a great YouTube video on this topic as well:
White has two threats: the mate threat (Qxh7) and the capture on d4 (Qxd4). The mate threat takes priority, but ideally black would like to find a move that prevents mate while also defending his bishop. In subsequent posts we'll go through the calculation process to find black's best response. For now though let's just focus on identifying and prioritizing the threats.
Some positions are more complicated, such as the following:
White has two threats -- to mate on f8 (Rxf8), and to play Qe5 creating two new threats for a total of three: to capture the queen (Qxc5), to mate on g7 (Qxg7#), and to mate on f8 (Rxf8) if the queen moves. The mate threats are greater than the threat to the queen. Here it does not matter whose turn it is to move and we're not calculating defenses yet. We're just looking for all the threats we can find.
It is also very important when you are assessing the threats that you take time to make sure it is a real threat. To do that you need to calculate a bit. The trick I recommend is to skip your turn, and allow the "threat" to play out in your mind. At the end of the line you can ask yourself what you could do with an extra move (the one you skipped).
Take this postion for instance. White just played Nf3. Find and prioritize white's threats:
One might look at this position and see white's "threat" to play Nxe5, winning a pawn. But before we start calculating how to deal with that "threat", let's skip our move and visualize the position after Nxe5. Is it any good? Has white just won a pawn? Are we just sacrificing our pawn for some sort of initiative? Anyone who has studied some tactics should quickly find that black has the immediate queen fork (Qa5+) hitting the king and the now loose knight on e5. There is no way to deal with the check and defend the knight at the same time, so black wins a knight for a pawn. Therefore, black does not/not need to address the threat to e5, and can go on with any regular move that doesn't block his queen fork, such as 0-0.
You could also say that the pawn on e5 is tactically defended, but in order to see that you have to allow the "threat" to play out in your mind (unless you already know the pattern, or the specific opening in this case...that all comes through training and experience).
Keep in mind both of these steps as you play: (1) find and prioritize all threats, and then (2) make sure the threats are REAL!! Cecil Purdy calls this "recognizing the unreality of their unreal threats".
IM Andrew Martin has a great YouTube video on this topic as well:
And here is a fun position I came across today. White just played 1. Rd1. Is 2. Rd8+ a threat?
Great post again! :)
ReplyDeleteDiagram 1
1.What is a threat?
2. Are there many threats than these two you mentioned?
3. Is Qxb7, Qxe6 any kind of threats? What about Ba6?
Diagram 2
1. Why 1.Rxf8+ (you said "mate") is a threat? Why is it "a mate threat" if after 1.Rxf8+ the Black Queen can take the Rook? (1...Qxf8)
2. How did you find the move Qe5? What was the reason for that?
3. Why haven't you considered such moves as: Qe7, Qe5, Qe3, Qc4, Qc2, Qb2?
4. What about looking at Rf7 and seeing if it can create some threats? (Rxg7, Rxb7, Rxf5 comes to mind)
5. What about Qe6, Qe8 or Be6? Are these threats or not? Why? Should we take these into consideration? (as our candidate moves)
Diagram 3
1. How can you know if there is ANY refutations to the specific move? How many moves ahead we should look into? Are there are hints?
2. Is Bxf7+ a threat? What about Bf4 (attacking the undefended pawn twice)?
3. How can we know if we discovered all the threats in ANY position?
4. How can I know HOW we can refute any move? Are there any specific methods when looking for a refutation(s)?
I would be VERY glad if you could provide the answers to my questions. Your thoughts are very inspirational to me - the more you share the more I can learn about! Thanks in advance! :)
Hi Tomasz -- thanks again for your questions.
ReplyDeleteDiagram 1 questions:
A threat is anything that could change the material/activity situation on the board like a mate, check or a capture, or a threat to do one of those things. But threat can also include "positional" things like preventing castling, creating a weak pawn, controlling a file/diagonal, etc. As you improve, you will learn how to see more threats, but at first you should focus on mates and captures.
I don't see any other threats in the position other than those two. Can you find any? You proposed Qxb7, Qxe6, and Ba6. Those are candidate moves that you should calculate deeply enough until you convince yourself either way whether they are threats. Be specific. What does white win by playing those moves? Can you find a refutation for black? My recommendation for these positions is to skip black's move. So in the diagram white just played Qe4. Skip black's move, and allow your three threats to play out, so if 1. Qe4 (skip) 2. Qxb7, does black have a refutation (remember, look for black's best moves, and his most forcing replies first)? If black does have a refutation, then Qxb7 is not a threat. If you find white gets something good, then you can add Qxb7 to your list of threats along with the mate threat (Qxh7) and the threat to win the bishop (Nxd4 or Qxd4). You would then prioritize those threats, with the mate threat being the most important, and calculate black's five defensive ideas.
Diagram 2 questions:
correct, Rxf8 is not immediately mate...it is merely a mate "threat". If not for the queen, white would have mate. That tells you a LOT about the position. The more kinds of threats you visually "see" on the board, the better attacker/defender you will be. But you have to try to "see" all threats that you can and take time to understand the relationship between the pieces.
I found Qe5 by first noticing the Rxf8 mate threat. Then I saw the queen cannot leave the defense of the rook for anything (other than going for mate), even if it wins white's queen. So I knew I could attack black's queen with anything, including my queen. But a single attack against the queen can be easily refuted. What is better than a single attack? A double (or triple) attack! So I then looked for other threats the queen can create and saw the mate threat on g7 (see my other post on creating threats by looking for squares around the opponent's king that you are already attacking, and see if you can add an attacker). This is "offensive" chess which requires you to study tactics!! My blog so far has really only focused on calculating the defensive side of forced variations because they are so limited (to only five ideas).
The other moves you propose could be threats too! You should calculate each one a bit, and determine for yourself whether (1) black has a clear refutation, or (2) white can win something specific. Remember skip a move, and calculate as deep as is necessary to convince yourself if it is a good/bad move. If any move creates a specific threat, add it to your list of candidates to fully calculate.
Diagram 3 questions:
ReplyDeleteThe only way to know if there are any refutations is to calculate, and you need to calculate as deep as is necessary until you can convince yourself of who is better. You might get it wrong -- you might not look deep enough, you might look too deep, or you might get the evaluation wrong. But the more you practice doing it, the better you will get. I promise!!! In terms of HOW to look for refutations, work through the five defensive ideas and see how you would evaluate the resulting position. Do NOT say things like "wouldn't it be great if my opponent played a bad move". You need to look for the MOST FORCING defensive replies first (so for example if you had one capture, one block, and one counterattack starting with a check as your defensive candidates, you should start with the check first, then the capture, and then the block last). That's it. You don't need to calculate any other moves than those five ideas.
Let's use your specific ideas (2. Bxf7+ and 2. Bf4) as examples. The question we are trying to answer is "what is the threat". White just played 1. Nf3 so it is black's move, but in order to evaluate the possible threats we will SKIP black's move to allow the threats to play out, and will look for any refutations black might have to either of white's possible threats:
1. Nf3 (skip) 2. Bxf7+
Black only has two legal moves, the capture (2...Kxf7) and the move (2...Kf8). There are no blocks possible because it is an 'in-your-face' check. Let's start with black's most forcing reply first (the capture) to see if it refutes white's threat, so now if 2...Kxf7:
white is now down a bishop for a pawn (two points), and black has lost the right to castle. So far it is not looking good for white but let's see what else white has. His most forcing move is the capture-check 3. Nxe5+.
Now black is in check. He cannot capture the knight, it is not possible to block a knight (ever), and he has four legal moves (3...Ke6, 3...Ke8, 3...Kf8, and 3...Kg8). I do not see any other threats for black to consider. Playing 3...Ke6 appears to be the most forcing because it attacks the knight. However, I would reject that move because I don't like having my king that exposed -- he could easily come under attack by most of white's pieces. I would prefer to move the king back to the 8th rank with say 3...Kf8. Now I cannot find ANY moves by white that worry me. I would stop calculating at this point and evaluate the position: Black is up a knight for two pawns (one point advantage), black has lost the right to castle, but has the threat Qa5+ winning the knight. I would prefer to be black in this position, so if I were black I would not consider 2. Bxf7 to be a threat because of the concrete variation above.
So what about 2. Bf4.
White has now added a second attacker to the e5 pawn (along with Nf3), which means black's Qa5+ won't work. Let's calculate black's five ideas looking for a refutation, so start with the most forcing move first. Black does have a check (Qa5+) but in this case the best reply for black is to capture the attacking piece (bishop) with 2...exf4. White can recapture the pawn, but I would evaluate black up a knight for one pawn (a two point lead). I would like to have this position as black, so as black I would not consider 2. Bf4 to be a threat (due to the refutation above), and white should reject 2. Bf4 as a candidate move.
Thank you very much for taking your time for answering my questions. Now my understanding has much less gaps :). Good work! Well done!
ReplyDeleteSkipping a move is a VERY useful idea (concept). And I understand much better what you means by saying "forced" and "refutation". Thank you so much.