This still fits my weaselly definition. Presumably, Alekhine would look at the opening position (as either White or Black) and without calculation would evaluate his position as being at least a P ahead without any compensation for his opponent :)

But then again not to make allowances for the idea of what I call 'circumstantial synergy' overlooks an essential reality of Chess.

Given that Alekhine apparently claimed a draw by 3-fold repetition around move 19. and that Reti had possibly winning alternatives from around move 27. by the time the stage was set for the swindle one must credit Alekhine for recognizing it but NOT 24 ply earlier as is presumed.

Reti gambled upon keeping the draw in sight - perhaps himself looking for a golden moment of transposition for an unseen nuance - which I qualify as being for all practical purposes a "fluke".

It is human nature to claim - after the fact - that all was seen beforehand. Regardless this was certainly the game of the 1st quarter of the 20th century.

I figured the rook on c8 and the pawn on e6 pinned to it by white's h3 bishop was the target. The immediate d5 didn't look like it accomplished anything, and then I noticed e5 seemed to cause problems for black's dark bishop. Bb8 loses because it isolates the c8 rook from its partner on a8. Bc7 is better, but makes d6 a threat once I play d5. So,

23. e5 Bc7 24. d5

and it looks like black has to take; exd5 gives up the exchange for no apparent compensation, so,

24. cxd5.

I was anticipating Nd4 to put more pressure on e6 (still fixated on the rook on c8, but in thinking about how to get rid of the knight on f8 that’s protecting e6, I finally saw that Bc5 is awfully annoying now that the bishop is on c7.

25. Bc5

I figured Qd8, because I was so enamored of my pin on e6. That makes a little difference, as on d8 the queen is vulnerable to a royal fork after the king retakes on f8. But the key point, of course, is that I did not see Qxh7 at all. Had I played slowly I have hope that I would have seen it over the board, but I didn’t see it here. Took me right at (3:20) to see what I saw.

This is my first post to a daily puzzle. Next time I’ll follow dezechiel’s lead (he’s taught me a lot) and write out my whole post before checking.

23 e5 Bc7
24 d5

but I am not sure black really has to play

24 ... cxd5

although it is what I expect. In this line

25 Bc5

then a lot of things can happen. I like white in this position but there is too much going on for me to say without an engine. So I don't think I can say I sovled this puzzle at all.

So Rybka continues with the line that turns the queenside into a free fire zone

25 ... Bd6
26 exd6 Nxd6
27 Qd4 b6
28 Bb4 Nd7
29 Ne5 Ne5
30 Bxc5 bxc5
31 Rxc5 Rxc5
32 Qxc5 Rc8
33 Qe3

Black now spends a tempo to take the pressure of the back rank

34 ... h6
35 g6 f5

White is up a bishop for a pawn can force black to accept exchanges. White will win.

Alas, neither puzzles is solvable within the parameters of the difficulty evaluation setup used for the earlier days of the week. My evals work reasonably well until Friday level, and I never had time to explore ideas for comparing the very difficult & insane level puzzles.

This said, I believe that today's puzzle is not that obvious as everyone thinks it is. For example, I see that nobody considered the possibility of 24...Bb6 which prevents white from skewering Q+N. The game could go thus:

23. e5 Bc7 24. d5 Bb6 25. d6 Qd7 26. h5 g6 27. h6 Bd8

click for larger view

and now black is completely cramped, but the situation is far from the forced loss as it was in the played line, and the advanced white pawns are more of a hindrance than help. There is no quick tactical solution, and the game will grind while white regroups to attack on Q side. I suppose this could be considered a matter of technique, but I doubt that many people below 2000 ELO posess such technique -- I sure don't.

Or consider alternate line:

23. e5 Bc7 24. d5 Bb6 25. d6 Qd7 26. h5 Rd8

resulting in (white to move):

click for larger view

Does anyone care to find the best continuation above?

<sfm: When a position is given as a puzzle we know that there "is something", and that makes it much easier to pick a dramatic continuation, instead of a more normal move. If the follow-up argumentation is not there it usually means that the player would not have made the move if it was in his actual game.>

<MAJ>: "I see that nobody considered the possibility of 24...Bb6 which prevents white from skewering Q+N."

True, I did not specifically mention 24...Bb6. I did, however, specifically mention its sequel, 25.d6, among my alternatives, but regarded it with complete disdain.

The move 25.d6 falls into that abyss, where computers rate a move "the best", but where very few human players would go without a gun to their head. Your two positions are both tactically dead, so effectively Black is down a B and an N with no opportunity to confuse the issue. Certainly, computer evaluation could factor in the pain of defending against Lajos Portisch for 20 moves in a position both dead and lost. Until then, however, computers and humans will continue to disagree about what constitutes a best move.

(Forgive me if I do not rise to your challenge of the best move for the second diagram. Even if it is a Saturday puzzle in disguise, a Sunday puzzle is enough for me today.)

Going by my own engine (Fritz 10), I think there might be some misunderstanding here. The sequence 24...Bb6 25.d6 isn't recommended by the engine as "best" for Black - in fact, it understands very well that it amounts to a positional death-sentence. Here's how bad it thinks it is: apparently Black "has" to continue 25...Qd7, since 25...Qd8 allows White to win a piece by 26.d7. But actually, both moves get similar evaluations, and after 25...Qd8 the engine doesn't even consider 26.d7 as White's best option - moves like Bf4 or h5, increasing the pressure without giving Black any "breathing space" get higher evaluations than the move which immediately wins material.

What <is> somewhat problematic with this line in the context of a "puzzle" is that it doesn't seem to lead to a win (or decisive gain of material) by a forced series of moves.

You are right. I assumed incorrectly that <MAJ>'s line reflected computer evaluation, and I realized only after I "spoke" that not even a computer would desire the slow but certain death that 25.d6 brings.

The possibility 24...Bb6 24. d6 is interesting, but I have to agree with the apparent consensus here that it looks like a slow but sure winning position for White.

I think I commented on this frustration in yesteday's puzzle as well... The earlier puzzles in the week tend to be simply forced wins (Up until about Fridays, usually), whereas... Take yesterdays or todays puzzle for example; the play is murkey, and it's hard to find a definite winning pattern because one doesn't necessarily exist, certainly not to human eyes.

But then these positions are thrown up as puzzles, whereas in games, you know the lead up to the position; you know your objective, what you've been trying to do all along, and you know how it is to be fulfilled - I think this is a vital difference.

This is why my attitude to fri/satur/sunday puzzles is different to that of my attitude to the other days in the week - If I find myself staring at the position for more than 30 minutes, I just look at the solution and appreciate the work of the player, rather than kicking myself for not seeing some obscure pawn sacrifice that leads to an attack or whatever.

Maybe 27. ♕b3, intending to attack the Q-side pawns this time. This leads to a very tedious game, whether White will be able to get a passed pawn through or whether Black can counter and prove that the advanced pawns will eventually become a liability. Either way, it looks like an uphill battle for the Black side. If the White side plays accurately, he will win.

And now that you guys mentioned those lines, I was wondering why many kibitzers found ♗c5 easily and yet did not find time to mention ... ♗b6 or ... ♘d6, both defenses against the ♗-sortie. Do I smell something fishy here?

This Sunday's puzzle is more of a tactical puzzle, which aims to break down a defense by removing defenders, compared to yesterday's puzzle which was more strategic (opening up a file, adding pressure to a weak enemy square, etc.) and from how I see it, tactical puzzles all the more require that you consider all possible defenses to your plan, no matter how lame those defenses may seem because they lose a whole ♖ or something. This is more important for tactical play because if the plan fails, it may backfire. Compare and contrast to strategic play, where the advantage gained may be more subtle or not readily tangible.

Honestly, I never saw those moves above because I had no clear idea what e5 and d5 was all about at first. I had no idea about removing the h7 defenders at all until I read the solution.

Perhaps all because I'm more of a strategic player than tactical? I don't know for certain. But I'm sure I saw b4 yesterday much faster than I even thought of playing e5, because here I had no clear picture of what I want to happen.

It depends on the human behind the eyes. Some people got today's puzzle easily: it had a smooth, positional logic. (I recall your post that anyone claiming to solve the weekend puzzles must look at the games first, but it just ain't so.) CG warns that the difficulty of the puzzles is constant over time, but it might seem otherwise because your solution skill improves with practice. A month of methodical practice makes a huge difference.

"I don't feel anyone should feel down about not getting the puzzles from friday onwards because [snip]"

...because there is always room for improvement :)

... ♘d6 refers to this line: 23. e5 ♗c7 24. d5 cxd5 25. ♗c5 ♘d6 26. exd6 ♗xd6 27. ♗xd6 ♕xd6 28. h5, where White has a piece versus Black's two pawns. I think this is not as simple as 'giving away a piece', since the resulting position for Black is not as bad as compared to the position at the 28th move in the text.

click for larger view

(17-ply) Rybka2.3.2a
1. (0.12): 12...e6 13.Bd2 Qc7 14.0-0-0 0-0-0 15.Qb3 h6 16.h4 Rd5 17.Qc2 Kb8 18.Kb1 Be7 19.Rg1 g6

2. (0.12): 12...Qc7 13.Bd2 0-0-0 14.Qb3 e6 15.0-0-0 h6 16.h4 Rd5 17.Qc2 Kb8 18.Kb1 Be7 19.Rg1 g6

black is underdeveloped but it seems he has a more playable game than 9...Nxc3.