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I calculated to the following position during a game:

[FEN "r1r3k1/5pbp/p2qpnp1/3p4/3P4/2N1PB1P/P5P1/2R1QRK1 w - - 1 22"]

At the time I believed black would have a slight positional edge beyond their extra pawn, the black queen is more active and the white rook on f1 is terrible - but white has ideas of improving the f1 rook and trying to trade queens. I guessed a computer might give the position -1.5 or -2.

Stockfish evaluates this at -4.3 (Depth 26), almost a full piece worse for white than I had assumed. What ideas am I missing in this position, are the positions of the queens really that important? What can I do to avoid this kind of misevaluation in the future?

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    While I woudn't be surprised to see a position like this evaluated at -2, I am a bit surprised that SF considers black to be so far ahead. This kind of "misjudgement" is not something you will be able to avoid consistently, no matter how strong you get. The best way to see why SF gives the eval it does is to go through some of the top lines until it becomes clear why black is winning, at this point we humans can merely guess why the eval is so extreme.
    – Scounged
    Apr 16, 2022 at 13:39
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    A -2 position will be a -4 position as more moves pass. What you're seeing is just the fact that Stockfish can see really far ahead and predict the way in which White is going to lose this game
    – David
    Apr 16, 2022 at 22:01
  • As long as you had the right evaluation, you should be happy. Numbers per se do not mean that much if you are thinking about human versus human chess.
    – user13438
    Apr 17, 2022 at 8:36

4 Answers 4

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What ideas am I missing in this position

In this position, not only is White down a pawn, White also has a backwards e pawn, which Black can easily exploit with its knight, queen and bishop. Especially since the Black bishop is dark-squared, the e3, d4 pawn structure can be easily broken. The White King is also quite unsafe, as what @briantowers has mentioned, as there are no pawns are dark-squares, leaving empty holes in White's position which Black's bishop can easily sneak into.

are the positions of the queens really that important?

In my opinion, at the moment the queen's positions are not really important, yet. Especially in the endgame, well placed queen's can lead to one's advantage e.g. controlling more squares, controlling the center, more space to attack.

What can I do to avoid this kind of miss-evaluation in the future?

When looking at a position, always evaluate the following in order (not 100% accurate)

  1. Material advantage (whether one side has more pieces than the other) (for exceptions e.g. rook vs N+B, evaluate the position and placement and if they are enough to compensate for the 1 point)
  2. Positional advantage (positioning of pieces)
  3. King safety (under positional advantage, in this case, where Black's king is quite safe, while White's king is vulnerable due to the dark-squared pockets in White's position
  4. Attack possibility (under positional advantage as well, King safety is usually top priority, unless your attack forces the opponent to do something else rather than continuing the attack on your king)

Evaluation of position

After looking using lichess stockfish analysis to make the best moves at depth 22-23, I came up with this

[FEN "r1r3k1/5pbp/p2qpnp1/3p4/3P4/2N1PB1P/P5P1/2R1QRK1 w - - 1 1"]

1. Na4 Rxc1 2. Qxc1 Bh6 3. Nc5 Rc8 4. Qd2 a5 5. Re1 Qd8 6. a4 Bf8 7. Rc1 Ne8 8. Be2 Bh6

As you can see, Black is constantly putting pressure on that weak e3 pawn, and White has no choice but to try to protect it. Additionally, if you're wondering, Oh, but White has an excellent outpost for the knight!. You're not wrong, but the problem is Black can easily kick it away or force a trade. Black has enough pieces (rook, bishop, queen, knight) to attack that piece and can force a trade whenever Black wants. Plus, the White knight is not really doing anything but sitting there.

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  • Please comment if i missed anything under the evaluation list (i came up with it quickly, so it is probably missing points)
    – DialFrost
    Apr 15, 2022 at 13:36
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I think that quite possibly we have here a case where the computer gives too high a numerical value to its assessment. Computers sometimes give high evaluations that they cannot translate into winning positions, for example, they often fail to recognize a fortress. Black is undoubtedly better, for reasons that others have given, but to be four points better, there should be a clear way to exploit that superiority, but I do not see it.

White has no aggressive play at all, apart from putting that Knight on c5, and they have weak pawns on a2 and e3 that need to be defended, so Black can pretty much do what they want, but what do they want to do? It has been well observed that chess games are not won by achieving good positions but by making strong moves. What are they? the SF "analysis" provided by @DialFrost is not inspiring. Has Black made any progress? Has the evaluation changed? What does SF want to do with its Bishop.

A "principle" to bear in mind is that "nothing is weak unless it can be attacked". and as things stand, e3 and a2 are inaccessible. @Dialfrost suggests that e3 can also be attacked by BN and BQ. But how? There is no way at present for BQ to join the attack, and although BN can manoeuver to the beautiful square f5 it can just be taken by the WB. How in fact should BN be used? The square d6 is attractive, with access to b5, c4, e4 and f5, but can be taken on any of those squares. Maybe the best use for BN is to exchange off Nc5.

Probably what I would do as Black is to follow @cousin_pete and try to penetrate on the b-file with my Rook and generate sufficiently strong threats that White is glad to exchange major pieces, so that BK can join in. Opposite Bishops do not always guarantee a draw. You need to visualize remote endgames to know what exchanges are desirable.

Something else to take seriously is an Exchange sacrifice on c5. The Pawn will fall also. so Black will have two Pawns for the exchange, and a diagonal along which the Queen and Bishop can operate against e3. Probably Black does not want to exchange a Rook before sacrificing, because after the sacrifice it will increase his opportunities to have one Rook remaining.

One way and another, there is a lot to be thought about in this position, and quite certainly it will not play itself. I believe that the OP is quite right to be puzzled because even if the computers evaluation is correct it would take GM-level play to convert it to victory with assurance.

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What ideas am I missing in this position

  1. King safety is probably the most important feature. White's king is very vulnerable with all the weak dark squares around it. Black's king is very safe.
  2. No White dark squared bishop to protect the weaknesses while Black does have a dark squared bishop to attack them.
  3. Opposite coloured bishops favour the attacker. In this case Black.
  4. White's backward weak pawn on e3 is much more vulnerable and hard to protect (no pawn help, on a dark square) than Black's weak pawn on f7 (can always advance to f5 for double pawn protection.
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Welcome Green!

What ideas am I missing in this position, are the positions of the queens really that important? What can I do to avoid this kind of miss-evaluation in the future?

As you note, apart from the extra pawn, Black's Q has more activity. I think the Black Q mobility in this position especially on the black squares may be decisive.

Let's look at plans for White: White is on the defensive and is trying to hold for a draw. A nice square for the White N is c5 so a plan could be N:a4 then N:c5 and await developments, exchanging pieces when possible, ideally hoping to get to an opposite B ending a pawn down with good drawing chances.

Black has several plans and will try to invade the White position via the open b file and semi-open c file with her heavy pieces. The c4 square looks very inviting to try to get the N there where it would be dominant.

If it is Black to move then Q:a3 (preventing N:a4) initiates one plan to follow with Ra8:b8 then to R:b2 then N:e8, N:e6 eyeing c4 (exact sequence of course depending on White's responses) and very soon White will be under great pressure.

Black has targets in the weak 'a' and 'e' pawns. I don't own a chess program to check but I suspect that the White position will soon collapse.

Perhaps you mis-evaluated the importance of piece mobility and that Black is able to systematically improve her position whilst White has to sit and wait.

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