Tuesday, March 3, 2015

Calculating Forcing Moves: Defensive Idea 4 (Defend)

When your opponent creates a (real) threat, or you are considering creating one against your opponent, there are five defensive ideas to consider.  We have already looked at different ways to implement the first three defensive ideas:  Idea 1 (capture the attacking piece, pin the attacking piece, deflect the attacking piece), Idea 2 (block the attacking piece), and Idea 3 (move the piece being attacked).  This post will explore the fourth basic idea of defending the piece being attacked.

This is another pretty straight forward idea -- your piece is being threatened and you find other pieces that can move to defend it.  This usually happens when the piece is loose (or just underdefended) you don't want to or can't move the piece for some reason.  The search method is simply to look for other pieces/pawns that can move to defend the piece.  Add those specific moves to your candidate list to calculate further.

The idea of capturing/defending brings up another important element of piece safety -- counting.  In its simplest form, the "count" is the number of attackers vs the number of defenders.  However, in addition to the simple quantity of attackers/defenders, there are also issues of quality, which may trump quantity, order of recaptures, and also captures on several squares.  This is a topic for another entire blog series, but it is very important to know the basics anytime you are considering defending a piece that is being attacked, and is hugely important when considering counterattacks (which we'll look at later).

Let's start out with a simple position to demonstrate the idea.  The general process is to evaluate the position, identify and prioritize all threats, and then use the five defensive ideas to identify specific candidate moves.  Next, calculate each candidate move to the end and evaluate the final positions (material and activity).  As you progress through the candidates, keep in mind the "king of the hill" (KOTH) candidate move to help you pick the best at the end.

Black just played Qf5 attacking White's rook.  White to move.

2kr4/1pp2p2/p4p2/5q2/4RP1Q/P1P3PR/1P6/1K6 w - - 0 1

Let's evaluate the position and then find all of white's threats.  White is up an entire rook, and black has no clear compensation.  White is playing to win, while black is fighting for a draw.  Black's immediate threat is to capture white's rook with the capture-check Qxe4+, restoring the material balance, and black will be slightly better because of his more actively-placed pieces.  Black has no other threats.  If white can keep his rook, he is clearly winning.  Let's look at the five defensive ideas to see what candidate moves we find, and then pick the best move.

Idea 1 (capture, pin, deflect):  no captures; 1. Qg4 pins the queen to something more valuable, but it is unsafe.
Idea 2 (block):  none.
Idea 3 (move):  none -- the rook is pinned to the king and cannot legally move.
Idea 4 (defend):  searching the board it is not immediately clear if white has any mvoes that defend the rook.  It is tricky to find, but it is there!  Highlight to see the answer: [1. Qh7.]
Idea 5 (counterattack with an equal or greater threat to WIN, DRAW, DEFEND):  an equal threat would be to win black's rook for nothing, but that is not possible here.  A greater threat would be to attack the queen or the king, but there are no checks and we've already considered 1. Qg4.

The tricky part of this position is not the calculation, so I'll skip further analysis since white is now clearly winning.  If you couldn't find the move (but you did look), try training positions using the x-ray theme until you never miss them again.  This idea is very important to remember -- if you find that you are "missing" moves, try to really understand if you missed them because you didn't even look, or you looked but didn't see.  Those are very different problems to have, but both can be trained.

This is the last blog covering the basic four ideas.  The next blog series will cover the very exciting and complex fifth idea of counterattacking!


  1. "Black just played Qf4 attacking White's rook" --> you probably meant QF5.

    Idea 4 (defend) + Idea 5 (counterattack) = SOLUTION! :)

    You can defend a Rook with an X-ray theme and counterattack the Black Queen in one move! Have you considered this special "two fold-ways" move?

    Your examples look easy and simple. However when you start explaining ALL the ideas and their relationships - it is really FANTASTIC to see all these tricks, concepts and nice analysis. I am trying to find refutations, but it is a really hard task. Most often I can just find some "missed analysis moves" (like here 1.Qxf6, 1.Qg5, 1.Qh5, g4 - attacking the Queen, etc.), but I believe you omit these as they are not interested - am I right?

    Looking forward to your next posts - I have NEVER read such a well structured chess lectures. You remind me of Dan Heisman's teaching, but your lectures are more creative and better explained. At least I see it this way! :). Keep up great job my friend!

  2. Thanks for catching that! I've made the correction to Qf5 :)

    You're right, the move Qh7 does indeed do two things (defend the rook AND attack the queen), which makes it a pretty forcing defensive move! But the key to finding Qh7 is knowing to search the board for moves that defend the rook...the attack on the queen is just icing on the cake :)

    Regarding those four candidate moves you gave (Qxf6, Qg5, Qh5, g4) they do appear to be forcing and in the classic calculation approach of considering all checks, captures, and threats, I can see why those would come to mind. But I never really liked the CCT approach, and my recommendation is to consider ONLY those candidate moves that relate to the threat (using the five defensive ideas). In the above position black is threatening to capture white's rook with check, and none of those four candidates address the threat. I guess you could argue that they counterattack the queen with an equal threat (or greater in the case of g4), but a quick calculation of those lines show you that black can easily refute all four with the original threat (Qxe4+).

    Thanks again for the compliments, and I have not forgotten about your request to put these ideas into a table. I have been playing around with different formats but haven't found one I really like just yet.

  3. Thanks for your explanations - they are really nice and useful. I would like to remind you that I ask non-standard questions to HELP you express your thoughts better and to find any kind of additional inspiration. Of course your method is very good and I appreciate it very much. However I used to look at refutations and exceptions and that's why I am asking some questions that "should not be asked".

    I would like to be your reviewer and if you post enough material we exchange the emails and will make some kind of book. If you would like to share it (for free) or sell it - it is only your choice. Such a GREAT material with a fantastic form may not be "lost" - it is more than necessary to make it in a coherent form (a book, e-book or other form).

    I have read about a few dozens of books and visited a few hundred of websites (blogs included) and I have NEVER seen such a solid approach to explain "simple things" in a very practical, logical and useful way!

    And of course you can share the table at any time you wish. It is better not to hurry as this table should be "non-refutable".

    To sum up: your posts are great - I find them really inspiring and always think over all of the ideas you share. Thanks for that my friend! :)

    1. I do appreciate your questions...including those that "should not be asked"! It helps me think through the ideas and the approach. I dont' know the first thing about publishing, but once I get this series finished I might look into it. Thanks again for the encouragement and praise!!