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| Posted by andy94 play-chess-online.com 10/17/2008 08:54:35 play online chess |  Subject: Pieces score in endgames.Message: I've found another thing. During the endgame 2 rooks draw against a Queen (they can even win!!)! It's true it's up to the game that one player is playing, but that's a concrete fact. So, I think a bishop is 4 points, a rook still 5, a Q still 9, a knight 1.5 points and an isolate pawn 2 points. Am I crazy or.....??? |
| Posted by blake78613 play-chess-online.com 10/17/2008 09:10:37 play online chess | Message: |
| Posted by andy94 play-chess-online.com 10/17/2008 12:04:49 play online chess | Message: Anyway, Blake, I saw your last annotate game.....Have you really played face-to-face against THE LEGEND? Well, I'm sorry for the defeat, but he was, he is and he'll be a true legend. Other than Kasparov or Karpov or someone else. Thank you for replying. |
| Posted by blake78613 play-chess-online.com 10/17/2008 13:03:54 play online chess | Message: |
| Posted by tugger play-chess-online.com 10/17/2008 13:06:10 play online chess | Message: "The pawn in blockaded by the king and when the king has no move the king is moved so the inferior side has the pawn to move. " This might be incorrect, in my experience, it's a Knight that blockades, while the other Knight and the King trap the opposition King. Perhaps I am half wrong though, maybe it is possible to trap with two Knights while the King blocks the pawn, I just haven't seen this yet myself. As for the issue regarding mate with just two knights against a lonely King, the King can blunder into a mate, for example... 1. Na6+ Kc8? 2. Nd6# Clearly, Black makes an idiot move, but it does show that Black can blunder into a mate against two lonely Knights. Of course, it's highly unlikely to happen, simply because the game should have been agreed as a draw by now, perhaps even a forced draw, I'm not entirely sure whether Black can demand a draw here, or if White can force him to play out the 50-move rule. Perhaps someone else can clarify this. I'd have a look into it myself, but I'm going to the pub. Have a good weekend! |
| Posted by ionadowman play-chess-online.com 10/17/2008 13:39:28 play online chess | Check out ... Message: Here it is in a slightly adjusted form: w White to play and mate in 9. Note that there is no one single solution (unlike most puzzles). Clearly, then, given the right conditions, 2 knights can win! But even a single knight can win - again, given the right conditions: w 1.Nxf7+ Kg8 2.Nh6+ Kh8 3.Qg8+ Rxg8 4.Nf7# It does seem possible that the value of the Exchange lies more in the middle than the endgame, so andy94's thesis that maybe the values have to undergo an adjustment seems quite valid. The lone rook cannot as a rule beat a lone bishop, nor a lone knight (though this is perhaps a little harder for the defender to hold. I seem to recall that David Bronstein once played out and won a R vs N ending; and that Judit Polgar once lost the knight side (against A. Karpov? - I'm not sure). I have won a R vs N endgame myself, by going after the knight. It seems likely that, though it didn't look like it at the time,the position happened to be winning for the rook. But there are other endgames. recall that a white pawn on a7, c7, f7 or h7 will draw against the Black Queen, provided the Black King is out of the play: Consider this position with White to play w White plays 1.a6 h1=Q 2.a7 ... and how is Black to stop pawn? 2...Qh8+ There's really nothing doing with the flank check, but Black can revert to the file easily enough: 3.Kb7 Qb2+ 4.Ka8! ... Now we have a stalemate position, but with Black to move. The BK can't move as then it would in fact be a stalemate, so the BQ has to get off the b-file. 4...Qc3 5.Kb8 This can go on indefinitely. I recall this as being a profound discovery when I first encountered it. The c-file position is even tastier: w 1.c6 h1=Q 2.c7 Qb1+ 3.Ka8 ... (White foreshadows his plan) 3...Qc2 4.Kb7 Qb3+ 5.Ka8 Qc4 6.Kb7 Qb5+ 7.Ka8 Qa6+ 8.Kb8 Qb6 9.Ka8!! Draw! White can not take the pawn, on account of stalemate (that the Q can administer a stalemate on its own is significant). The BK can not approach as the pawn then promotes. Note that if the BK were close enough at hand these drawing schemes don't work. Nor do the b-, d-, e-, and g-pawns have this stalemating resource available to them, so even with the BK far off, eventually the BQ forces the WK in front of the pawn, whereat the BK can approach. It's a long process, but not difficult. ll this might mean, then, that the a-, c- etc pawns ought to have a higher p"points value" than the other 4. But then, we know that a K+a-Pawn (or K+h-pawn)can not win against a lone king, provided the lone king can reach the queening square. But how about this? Can two pawns beat a rook? w 1.d6! ... wins for White! If 1...Rh6 2.d7 or e7 as White chooses; If 1...Rd6 (say), 2.e7 (or d7). Just by the way, the pawns don't need to be on adjoining files to beat the rook! If the pawns are further back, three will still beat a rook: w 1.g5! Rf1 (I'll just include this example...) 2.e6 Rxf5 3.g6! Re5 4.g7 etc. Finally (although this is still just scratching the surface), it is generally said that the bishop is better than a knight in most endgames - especially if the board is fairly open, and there is material on both flanks. However there is one interesting exception: endings that feature Queen, minor piece and pawns. It turns out that in such endgames, the knight is more often the preferable piece. This is because the knight and queen complement each other so well. A bishop augments the queens power on its own colour squares, but is often no help at all on the opposite coloured squares. I'm glad this thread has been opened. I have almost always had a fascination for endings featuring more-or-less balanced but asymmetric material. In the middlegame, B+N is said to be a balance for R+2P. But for an endgame featuring exactly this material distribution, check out the annotated game sago vs ionadowman (you can find it on my list of games via my profile, if you're interested. Cheers, Ion |
| Posted by blake78613 play-chess-online.com 10/17/2008 16:04:52 play online chess | Message: |
| Posted by tugger play-chess-online.com 10/18/2008 21:59:06 play online chess | Message: Quite. It wasn't ionadowman who pointed this out to you, either. Another senior moment? Certainly pawns go up in value in endgame, and I agree that without Queens on the board and an open position, Knights go down in value. So I tend to agree a pawn is worth 2 points. Perhaps a Knight alone is worth 2, and with a Queen 2.5, perhaps even 3. Maybe a Bishop is worth 4 points, but a pair of Bishops 8.5. But what if we have Q vs N+N? That's 9 points against 6 points max. But in most positions where the Knights are protecting one another, it's a draw. I think each endgame would yield different values for each piece. In Q vs N+N, the Knight pair are worth 8.9 if the Queen is worth 9. Interestingly, Q vs B+B seems to favour the Queen, so it seems in terms of defence, the Knight pair can be stronger than the Bishop pair, since the Bishops cannot protect one another. Finally, as a side note, in extremely rare circumstances, K+N vs K+P can be a win for the the sole Knight... 1. Na3 a3 2. Nc2+ Ka2 3. Nd4 Ka1 4. Kc2! Ka2 (if a2 then Nb3#) 5. Ne2! Ka1 6. Nc1 a2 7. Kb3# |
| Posted by ionadowman play-chess-online.com 10/18/2008 23:34:04 play online chess | A very nice study... Message: 1.Nb4! ... forces a pawn move 1...a3 2.Nc2+ Ka2 3.Nd4 Ka1 4.Kc2! Ka2 5.Ne2 Ka1 6.Nc1 a2 7.Nb3# All of Black's moves were forced. Although this is a very rare kind of endgame, knowing this kind of thing can create for you opportunities in real endgames, allowing you to switch from a seemingly drawn position into a winning one. Suppose, for instance, you, as White, found yourself in this position with Black to play: b It's a bit unusual for Black's K to be in such a strange position, but not unknown by any means. Suppose Black plays 1...a4!? To your horror, you realise 1.b4 a3! and White can not prevent a stalemate. But now, knowing tugger's line you can take on a4, knowing that the N vs P ending is winning for White. Black does have the sneaky option of not recapturing, but White still wins: 1...a4 2.bxa4 b4 3.a5! b3 4.Nc3 b2+ 5.Kc2 and wins quickly. So, a pawn move won't cut it. How about a K move? 1...Ka2 2.Kc2 a4 3.b5 Ka3 4.Ka2 Nc7! 5.a3 Nxb5 and the a-pawn is lost. Even after the better 2...Ka3, the ending is lost for Black: 1...Ka2 2.Kc2 Ka3 3.Kc3 b4+ 4.Nxb4!! (this is another one for your endgame repertoire) 4... axb4+ 5.Kc4 any 6.Kxb4 and wins easily. |
| Posted by tugger play-chess-online.com 10/19/2008 07:53:16 play online chess | Message: Your study is an excellent one, I had a sneaky look at a tablebase to see if there are other lines, and to confirm it is indeed a win for white, and it is, in 13 moves. Brilliant! I posted a puzzle last night also, along this theme... Of course, due to our discussion here, we all know the first move, but without this knowledge, we would assume that 1. Rxa4+! draws, since we are left with what we consider to be insufficient mating material. The natural line would be 1. Rb1+ Ka2 2. Nc3+, which of course also wins for White, but not as quickly. I had deliberately put the Knight on d5 in order to lure people into thinking that the fork was key, of course the Knight can be anywhere where it can reach b4 in one move. Anyway, they're on the parade lap. I'll be back to gloat after! |
| Posted by andy94 play-chess-online.com 10/19/2008 08:01:38 play online chess | Message: |
| Posted by tugger play-chess-online.com 10/19/2008 18:06:07 play online chess | Message: |
| Posted by andy94 play-chess-online.com 10/20/2008 06:46:50 play online chess | Message: Anyway, I want to correct Ionadown in his penultimate comment: in the board in which there were Black king on a1 black rook on h1 and e5, f5 and g4 white pawns best move for white is f6! Andrea. |
| Posted by tugger play-chess-online.com 10/20/2008 12:19:02 play online chess | Message: "To your horror, you realise 1.b4 a3! and White can not prevent a stalemate. " On further study, 1. b4 wins for White also... 1... a3 2. Kc2 a2 3. Kb3! Kb1 4. Nc3+... and it's easy from here, if instead... 2..... Ka2 3. Nc3+ Ka1 4. Kb3!... and again Black's pawns are finished. But in terms of quickest win, 1. bxa4! is still best by 7 moves. andy... I'm not sure anyone can ever be the driver Schumacher was, but Hamilton does have age on his side, so perhaps he can emulate the great. If McLaren can continue to provide him with a competetive car, he should win many titles, he does appear to be better than his current rivals. Maybe Ferrari should bring in Alonso, as much as I dislike him, he's probably the next best driver after Hamilton. |
| Posted by andy94 play-chess-online.com 10/20/2008 13:01:30 play online chess | Message: I know this is a chess forum, but.... Tugger: Hamilton better than Alonso.......c'mon! Maybe in 4 or 5 years, but in this moment best driver is Alonso...I still can't know why the hell Ferrari doesn't replace Massa or Raikkonen for him. Oh Anyway, there's only the Brazilian race to finish.......Hamilton 's got 7 points on a Ferrari driver.....Do you remember something 'bout it ?!?!?! |
| Posted by ionadowman play-chess-online.com 10/20/2008 13:11:58 play online chess | tugger... Message: andy94 is correct that 1.f6 also wins in that 3P vs R diagram, but I wanted to indicate that 3 pawns in a row will beat a rook (assuming kings are out of the play). I don't agree that 1.f6 is better; just that it's as good. I can understand your admiration for Mr Hamilton. Very fine driver, and it can't be many who came so close to the World championship in his rooky year. As for his being "up himself" - he's young, he's successful, he's earned his dues already. At that, I've seen heaps worse from many who have less to boast of. I think he does try not to be, you know. But then, I don't follow F1 very closely. I do follow the Indy cars a little bit, but that's only because it features our very own Scott Dixon... Cheers, Ion |
| Posted by tugger play-chess-online.com 10/20/2008 15:17:08 play online chess | Message: andy... I base my comparison of Alonso vs Hamilton based on their performances last year in the same car, coupled with their performances with different teams this season. There was a point in it I believe last year. Hamilton has matured this year, though he is still prone to recklessness from time to time, as we saw last weekend. But then his performance in the last race showed he is capable of being calm and disciplined too. Fernando is doing a great job in an inferior car, and the Renault might well be competetive next season, or maybe Ferrari will change drivers, but this will be difficult, since Massa has established himself as their #1, and Raikkonen is current champion with a long contract. So we will see. But I do accept I might be prone to a little bias. I guess it's only natural. Alonso is still young too, and improving every year. I cannot ignore that. And McLaren are certainly poorer for quality without him. But Hamilton has finished above Alonso two years running now. Yes, there is still a race to go, and McLaren need points for the constructors, so I don't think Hamilton can afford to play for third and allow the Ferraris to stay ahead without a fight, but he won't be taking too many risks, that's for sure. I just hope there are no dirty tactics. ion "At that, I've seen heaps worse from many who have less to boast of." I think this is a very fair comment. Perhaps I expect too much of him. As long as he's winning, I shouldn't care how he comes across on TV. Anyway, let's get back onto endgame discussion... We can talk about F1 again next week, when we know who won! Here's an interesting endgame position... This looks as though Black should be able to fight for a draw here, but in fact White can mate in 5. Again, here we throw the book out of the window, and a sole Bishop wins after a brilliant sacrifice... 1. Bd5+ Kb1 2. Ba3! b4 3. Bb3!! bxa3 4. Bc4 a2 5. Bd3# It's worth noting that Black is in zugzwang every move. It might be an unlikely position, but this kind of knowledge can be the foundation of a surprise sacrifice, such as a Rook for Knight trade. I think if I added a Rook to this position, it was too simple for White to win, but I'm sure this position could be expanded to create a fairly balanced, realistic endgame in which one subtle mistake from Black allows White the chance to force the position into the one we have above. |
| Posted by ccmcacollister play-chess-online.com 10/21/2008 13:02:03 play online chess | I think I'd agree with that Message: But it is never worth less than two pawns unless one is going to Queen. A N can stop two pawns whether they are distant or connected if both kings are distant (unless they are to the six rank i believe it is when one can sac itself to displace the N to Q the other. ) or both kings involved. If the N's king is distant and the pawns king involved the pawns may be able to win. I think absolutely should win if the other K can not get involved in time. |
| Posted by ccmcacollister play-chess-online.com 10/21/2008 13:23:43 play online chess | hmmm Message: (ala Tal for one) of trading a Rook for N ... thus leaving the other side with a Rook and you with a N ... is not made Speculatively unless the board is full or nearly so. Is done in the Dragon a lot vs the Yugoslav attack for eg. From this thought, perhaps it should also be said, Rooks will get stronger as the game goes on, in general, especially connectible. As long as on the subject, lets add that Knights crave an outpost. It makes them stronger than without. (...usually haha. Meaning don't outpost on a3, unless it Wins of course!! :)) |
| Posted by ccmcacollister play-chess-online.com 10/21/2008 13:43:02 play online chess | ion ... Thanks! Message: If true this would be nice for considering three pawns on the fifth. For doesn't that also work if they AVERAGE the fifth for eg 4th, 5th, 6th ? unattacked at least. I'm sure it does. Since logically it seems the three could always get two to the sixth ... or AVERAGE THAT anyway! (This feels like an epiphany, perhaps the first GM-erly efficient endgame thought i have ever had. Now I only need to create that position in every game, and . . . well, learn the square of the pawn :)) |
| Posted by ionadowman play-chess-online.com 10/21/2008 22:34:54 play online chess | Craig... Message: This motif cropped up in one of my GK games earlier in the year. w My opponent (id-webb31620, playing Black) had just taken 41...Rxf2. White maintained his two-pawn advantage with 42.Rxd6!, since Black could not recapture owing to the 2P vs R "rule": 42...cxd6 43.b6 or 43.c7 both win for White. Instead, Black tried his luck with 42...Rf1 43.Kg2 Rb1 44.Rd7+ Kf6 45.Rxc7 Rxb5 and though still with a considerable disadvantage, remained in the fight. Your comments in respect of exchange sacrifices for endgame advantage coincides with another reminder I got today of the final round game of a weekend tournament 29 years ago this very day. My opponent I think was a former North Island Champ, and we were both in line for a share of the prizemoney. Here's the plot: White: Me Black: LC Sicilian Defence 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6 6.Bg5 Bd7 ... Not expected, but nothing (it seemed to me) to concern myself about... 7.Qd3?! ... Keres's old line, not as good as the normal 7.Qd2, but I liked it. 7...Rc8 8.Be2 Qa5 Nope. Alarm bells still not ringing... I should have "got in" Bxf6 somewhere hereabouts. 9.f4 Nxd4 10.Qxd4 Rxc3!? w What the...?!? I hadn't a clue what was going on. Hence my decision to exchange Queens - to reduce the enemy attacking potential. Objectively, White ought probably have kept Queens on. 11.Qxc3!? Qxc3 12.bxc3 Nxe4 13.Rb1 Nxg5 14.fxg5 Bc6 15.Bf3?! ... Played to "undouble" the g-pawns if Black took on f3. Better was 15.Bb5. Black continued 15...Kd7, however. For the exchange, Black has got only one pawn, but he also got a much superior pawn formation and an easy game, by the look of it. It was certainly hard to see that White had any winning chances. The bishops came off shortly and we were into an endgame before 20 moves had been played! As it happened I was lucky enough to win the game, but might equally well have lost it. It was certainly a tough and dour struggle! Another "Exchange" ending took place on GK two or three years ago until this position was reached: b Having just cleared out White's K-side pawns, the Black rook desperately tries to get to the "back rank" to stop the b-pawn. No good is 43...Rc1+ 44...Rc8 on account of 45.Ne7+. What can Black do? 43...Rb1 44.Nb4! Bang. That's it. Black can not win. 44...Rc1+ And now with 45.Nc2! Black keeps out the rook and Black has nothing better than a perpetual. 45.Kd4? Rc8 After this, I was sure I was going to win. But there's a long way to go! 46.Kd5 h4 47.b7 Re8! Cuts the K off the K-side. 48.Kd6 h3 49.Nd3 h2 50.Nf2 ... It looks as though this must be a draw - or even a win to White, since the BR must eventually be given up for White's b-pawn. How can Black clear a path for his own pawns? 50...Kg7 51.Kc7 Kg6 52.Kd7 ... This looks as though it loses time, but it doesn't in fact. Black loses just as much time. 52...Rb8 53.Kc7 Rxb7+! Maybe White was hoping for a perpetual? Now White uis material ahead, but I knew that White's b-pawn was worth way more than a rook! 54.Kxb7 Kg5 55.Kc6 Kh4 56.Kd5 Kg3 57.Ne4+ ... Realising that the ending was hopeless after 57.Nh1 Kg2 58.Ke5 Kxh1 etc The knight might yet prove awkward for the BQ to overcome... 57...Kf3 58.Kd4 h1=Q Normal transmission has resumed: material advantage will win the day. 59.Nd2+ Ke2 0-1. After 60.Nb3 (say), Black simply plays 60...Qd1+ 61.Kc4 Qxb3+! 62.Kxb3 Kxe3 with an elementary win. These are the sorts of endgames I find most intriguing and exciting to play - endless fun. But to appreciate them, I guess you need to know quite a bit about what's "normal". Cheers, Ion |
Chess news: Bennett and King on chess: Barbero-Mohr, San Bernadino, 1989 -- White to play. Should he exchange rooks? RB I'm going to take - no hesitation here - and after I trade rooks with 1 Rxf7 Kxf7 I'm going to continue by giving up the exchange: 2 Rxc3 bxc3 3 Kxc3. My reasoning is straightforward: with the black bishop supported by the passed pawn on b3 it will be hard for White to make progress. After the exchange, the white king will get to the centre before its black counterpart, threatening the black e5-pawn and well placed to support the advance of its own pawns. I have to be careful not to make stupid pawn moves on the kingside that might allow the black king in, but this looks to me like a no-brainer: capture on f7, then ... Holiday chess -- For many people, the holidays were spent with family and away from work. Others opted to play chess. More than 600 people competed in the 18th North American Open in Las Vegas from Dec. 26-29. The Continental Chess Association, the organizer, noted on its Web site that the chess tournament is always held on those dates, "regardless of the days of the week." Giorgi Kacheishvili, a Georgian chess grandmaster, won the tournament, finishing ahead of a field that included 10 other grandmasters. In Washington, more than 200 chess players played in the 35th Eastern Open from Dec. 27-30, with Alex Yermolinsky, a chess grandmaster, coming out on top. Students from ... Barden on chess -- The USSR is long gone, but the Soviet chess school and its coaches continue to produce high-class chess grandmasters. Igor Kurnosov is hardly known outside Russia but the 22-year-old has a 2600+ rating and he took first prize at Hastings this week in impressive style. Leading scores were Kurnosov 7.5/9, V Neverov and E Berg 7, D Howell, S Conquest, M Hebden and S Williams 6.5. Kurnosov was thus half a point ahead of Ukraine's Valerij Neverov, Hastings winner for the previous three years, and a point clear of England's 18-year-old David Howell. Howell v Kurnosov two rounds from the end, when the teenager was only half a point behind and had the white pieces, proved ... | |