FEN viewer
Now we have discovered the trick, it is time to think about how we can acquire the trick more efficient?
The trick starts with a plan. The plan must be triggered by salient cues. How can we learn these salient cues the easiest?
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| Diagram 1. White to move |
5rk1/pQrnqppp/4p3/2bn4/4N3/2B1PP2/PP2BP1P/3RK2R w K - 0 17
Everything revolves around f6. Who are the defenders and how to deflect them?
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| Diagram 2. White to move |
Once you KNOW that everything revolves around f6, it is easy to come up with a plan.
- 1.Qxc7 to distract one defender
- 1. ... Nxc7
- 2. Rxd7 eliminating the second defender
- 2. .. Qxd7 distracting the third defender
- 3. Nf6+ luring away the 4th defender by a royal fork
This leads to the following position:
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| Diagram 3. White to move |
3. ... gxf6
4.Rg1+ Kh8
5.Bxf6#
I'm thinking about making a FEN viewer that helps to find the salient cues. In this case, you need the mate pattern (diagram 3) and the fact that everything revolves around f6 (diagram 2). Notice how simple it is to finde the moves one the salient cues are seen.
I read down to the diagram and decided to attempt to understand the “requirements of the position” prior to looking at your description. My basis for doing this was to determine if I could perceive the salient surface level cues pointing toward the essence of what to do.
ReplyDeleteGiven my tendency for “safety first,” I gravitated toward figuring out if I could wreak havoc with the queen before ignominiously retreating it to safety. Nothing immediately sprang into my mind. There must be some other factor(s) pointing toward the solution.
Hmm, WBc3 aims into the heart of the Black king’s position along the long diagonal a1-h8. There is a half-open g-file, also allowing an attack on the Black king. A “combination” of both these facts could indicate a possible stock mate. (I couldn’t remember the name; I had to look it up: Morphy’s Mate.)
The problem is how to open the g-file, since the WBc3 already occupies the long diagonal. The PoP is the f6-square; the BPg7 must be induced to capture on f6. At first glance, the WNe4 could be sacrificed on f6 IFF there are no other Black defenders of the f6-square.
BUMMER! There are 4 defenders of f6: BNd5, BNd7, BQe7 and, of course, BPg7. That brings to mind the idea of capturing to divert the defenders.
Suddenly, a role for the WQb7 springs unbidden into mind: capture the BRc7, “forcing” the BNd5 to recapture—the first defender is diverted away from the f6-square! As soon as I saw that, the next step immediately became obvious: capture the BNd7 with the WRd1, attacking the BQe7 AND controlling e7 and d8 as retreat squares for the Black queen. The second defender is removed!
OH NO! What if the Black queen skedaddles to h4? After WRxc7, White has gained two knights and a rook for his queen, more than enough material compensation.
So, Black will most likely capture BQe7xWRd7—the third defender is removed from the f6-square! Now a sacrifice of the WNe4 on f6 FORCES Black to capture it with the g7 pawn. Otherwise, Black will lose the BQd7 to the royal fork, followed by a fork of the BBc5 and BRf8 after WNf6xd7. Black would lose too much material.
After g7xf6, the stage is set for Morphy’s Mate: WRg1+, followed by WBxf6#.
That final sequence feels almost anticlimactic.
QED
After writing all that verbiage, I looked at the rest of this post to see what I missed. Not much, apparently. I note in passing that the process described is a quintessential example of GM Tisdall's variation processing.
I'm very interested in your idea of a FEN viewer that would identify salient cues. That is a great example of the kind of training tools we need!
I was hoping you got an idea or two too.
DeleteI'm working on a set of 100 problems from Ehrwichs book.I'm looking for salient cues, and whether there is an hierarchy in saliency.
Often it is a chain from the sitting duck backwards. What rules are there?
One of the things I’ve realized about the past few examples is that there is a sequence of thoughts that are in essence a cascade of consequences rather than a linear step-by-step thinking process. I really hesitate to refer to that sequence as a “rule” or a heuristic because the component elements vary drastically from one specific problem to another. However, there is a regularity to the sequence that is not necessarily obvious after a casual (NOT causal) glance.
ReplyDeleteThe sequence begins with an “obvious to the most casual observer (including club-level amateurs)” fact about the position. Let’s note that starting fact in the last two examples you have given. I repeat the FEN to avoid having to go back to the example posts.
1. FEN: 2r1r1k1/ppp1bppp/8/n4b2/2PPqB2/P4N2/4BPPP/R1Q1R1K1 w - - 0 18
2. FEN: 5rk1/pQrnqppp/4p3/2bn4/4N3/2B1PP2/PP2BP1P/3RK2R w K - 0 17
There is no commonality in the pieces-on-squares in the two positions.
In the first position, there is an obvious (and salient) tactical clue: the LPDO BNa5. Because it is an undefended piece, it is a magnet for attention, a “weakness.” That should automatically “trigger” a “search” for a way to exploit it. As we all “know,” directly attacking ONE loose piece with no other goal usually is a waste of time and will often misplace the attacking piece. There is a “chunk” associated with that BNa5: it involves BNa5 (with a “threat” on b3 to fork WRa1 and WQc1 [I overlooked this threat completely]), BPb7 (a potential defender), WPc4 [B.A.D. 1:1], WQc1 and WBe2 (defending c4). There is no other target available within that chunk. Ergo, we are going to have to find a different chunk in order to add an additional target and connect those two targets with a line of attack.
In the second position, there is also an obvious (and salient) tactical clue: it is the chunk associated with the WBc3, the open long diagonal (a1-h8), the half open g-file (with a White rook available to occupy it in one move), and the Black king position (the king itself and the g7 and h7 pawns protecting it). It is the confluence of the lines of attack through g7 (to g8 and h8) that should trigger recognition of a stock mating pattern. It is irrelevant whether we know the formal name of this mating pattern (Morphy’s Mate) or not. The label is useful for communicating concisely with others about this pattern but serves no function in the processing sequence. Once the stock mating pattern skeleton is recognized as potentially applicable, then the natural subsequent steps of the sequence will be to identify and eliminate all defenses of the f6-square.
Note that the initial identification of a standard “chunk” automatically triggers a standard response. In the first case it is to find or create a second weakness. In the second case it is to find potential ways to eliminate the identified defenders of the critical f6-square. As Nimzowitsch opined, we attack targets because any defender is weakened (constrained by function) by the mere fact of being a defender. The logic is inexorable.
The natural sequence moves from one recognized pattern to another, driven by the logical consequences of each observed pattern. That IS a “rule” that is always applicable. If a required pattern is “missing in action” within our repertoire or the required pattern is “known” but is occluded by tunnel vision focused on one aspect (or the wrong aspect) at any point in the logical sequence, then we will only find the solution sequence with great difficulty or through sheer dumb luck.
The logical narrative is a chain from beginning (the first move) to end (the sitting duck).
ReplyDeleteYou can start to pick up the chain at any point, and work your way forwards and backwards from there.
I'm looking for maximum pruning. If you start at the beginning, it is basically trial and error.
For to start in the middle, CCT is designed. Since every move must have a forcing element in it.
But there are situations where 80% of the forcing moves is irrelevant. So you introduce a lot of redundant checks (pun intended).
The best way is to start with the end. From K to g7 to f6 branching to e7, d7, d5 to c7. Notice how ALL branches are relevant.
So the question is: how do we know that g7 is relevant. What makes it stake out from other PoPs?
I'm 100% in your corner when it comes to maximum pruning! The fewer the potential moves/variations, the more likely we are to avoid mistakes and overlook something vitally important.
ReplyDeleteYou ask:
How do we KNOW that g7 is relevant?
In short, we don't KNOW at the beginning of our investigation. (I started to use "analysis" instead of "investigation," but that has connotations I would rather avoid.) As GM Tal once wrote [paraphrasing], "Something [some "chunk"] in the position is recognized as familiar and from that familiar chunk the chase of the bluebird of happiness [search for a combination] begins." That chase is NOT by trial and error nor necessarily by trying forcing moves until we either stumble on the proper sequence or we exhaust all options with no solution in sight. That initial familiar "something" guides the way forward, not just by trying forcing moves (although that is often the case), but by following a logical sequence such as "Here is a weakness. What resources are available in this specific position to take advantage of that weakness?"
All we do initially is recognize the outline of a KNOWN [to us] pattern that is potentially promising; familiarity breeds attempt.
Dr. Lasker contrasted the combination player with the position player by the direction of their thoughts: the combination player tries forcing moves, hoping to find an end point that is favorable. The position player has a favorable end goal in mind and works backward, hoping to find a viable sequence of moves that will lead to the end goal position. Neither type of player is right or wrong.
The play of the master follows a different path. Position play is completed by combination play. Combinations are available when one player has made moves not in keeping with the overall requirements of the SPECIFIC position; Dr Lasker referred to these as false values. Position play is based on the true values, which preclude the OPPONENT from wreaking havoc with a combination. That's why the great combination player Zukertort twice failed to defeat Steinitz for the world championship. Dr. Lasker categorized Steinitz as rather poor at combinations but magnificent at position play.
Perhaps that's just a PhD in philosophy musing in print, but I don't think that is the case.
Alright. But what do I tell my FEN viewer?
Delete