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Friday, January 30, 2015

Stockfish 6 vs. Komodo 8 (G5)

Here is a game from the aforementioned blitz match:

Stockfish 6 is out

 
Stockfish 6 is now available with Syzygy tablebase support. It is 50 ELO stronger than Stockfish 5 in self play. You can download Syzygy bases via torrent from Olympuschess.

EDIT: I ran a 7-game match of 5 minute games pitting SF6 against Komodo 8 using the Rybka2 opening book and the result was SF6 won by a score of +3 -1 =3. As usual SF's evaluations consistently ran higher than Komodo's. So, again as usual, SF's numeric evaluation does not directly compare to that of other engines which can be a tad annoying. I know that K8 is NOT optimized to play at a fast time limit; I am unsure of SF in this regard. All of which renders this little experiment useless, but still...  It will be interesting to see how things work out on the engine rating lists.

Thursday, January 29, 2015

Beware of Chess Engine Opening Books

 
Be more suspicious
  
 ...or any opening book for that matter. Engine opening books are made up from a database of games and engine play is significantly enhanced by the use of opening books. Most opening books are made by taking thousands of games and creating a database of the moves.
     Unfortunately many of the games included can be those of weak players, even near beginners, totally without regard as to the strength of the moves played. Even if the book was constructed using all Grandmaster games, the moves cannot always be considered good just because they were played by Grandmasters.  It's also quite possible the moves in the book are well past their "best if used by" date; recent innovations may have drastically changed a moves evaluation.
     When you build an opening book from a large collection of PGN games you run the risk of including a bad line that leads to an inferior position or even one that loses outright.  Of course a large collection of games is required to cover a reasonable number of possibilities that one is likely to meet, yet at the same time a large collection of games may well include serious blunders. This is why so many top level correspondence players spend an enormous amount of time fine tuning their opening books and looking for improvements. Most of us average CC players don't go into all that, but one still has to be careful when selecting opening moves in correspondence games. I ran into a good example of this recently in the Fritz 12 opening book.
     The line in the French Advance Variation is from Capa vs. Paredes and the book ends after 17.gxf5 and shows one game in the database that was won by white. Searching the database turned up the Capa game and so all his moves must be good, right? It turns out that the play after move 13 left a lot to be desired on both sides and so blindly following the opening book could easily result in disaster.
     This is an old story though. Back in the 1970's, before chess engines were even heard of, I was playing a correspondence game against an opponent who was one of the top OTB players in the US; he had even participated in a couple of US Championships. I was white and we were following the line in a popular opening booklet and I sent him my move copied directly from the booklet. Later I decided to look at the game because we were near the end of the book line and that's when I discovered a move that wasn't in the book for his next move. To me, it looked devastating. It turned out I was correct because that's exactly what he played. After the game (I lasted only a few more moves) he asked if I was using that particular booklet and when I said yes, he advised me, "There's a mistake in it."
     Always check things out for yourself and I am not talking just about chess. I am talking about everything. Never take someone's word for anything especially if the clues, or your gut, tell a different story. Someday I may learn this lesson myself.
     As for the game, there was something called the Havana "casual" tournament in 1901 that was apparently won by the 13 year old Capablanca. His opponent in this game was Leon Paredes, a prominent player of the day who served as president of the Havana chess club.


Wednesday, January 28, 2015

Najdorf and Reshevsky in 1953

I couldn't resist posting this clip of these two great players.


Tuesday, January 27, 2015

A Really Long Ending

     In the position below white has just captured my a-Pawn leaving himself with a won game. Komodo 8 says he's about a Pawn ahead and when I ran multiple Shootouts with several different engines, with the exception of a draw here and there, white won all the games in somewhere between 60-80 moves. With a time limit of 10 moves in 40 days, it could be a long game. But then messing around, I discovered something.


24...h5
The only way to get the R into play.
25.b5
Clearly, the queening of the P is the only way to go.
25...h4 26.Kxg2
White takes time to capture the P here because he wants to deny black the even the small consolation of having a protected, passed P.
26...Rh5 27.b6
White plays this logical move designed to eventully queen the P; his advantage according to Komodo 8 is about 2.25 Ps...easily winning even if it takes a while (60-80 moves). This is where I made a startling discovery.


27...Bxb6!!
28.Bxb6 Nxb6
29.Qxb6




      White's advantage is now over 3 Pawns, but I ran a whole bunch of Shootouts using the Houdini engine and even though white won the majority of the games, they averaged in length from 130-190 moves with most games being towards the 190 number! 
     At 10 moves in 40 days I don't really know how long the game could last, but it could be long time and maybe the guy will get tired of playing and offer me a draw

Monday, January 26, 2015

Jacob Bernstein

     Bernstein was a little known player whose early life, place and date of birth are all unknown; he died in December 1958. A book on the Rice Gambit, published in 1916, called him "a promising young master."
     After 1. e4 e5 2. f4 exf4 3. Nf3 g5 4. h4 g4 5. Ne5 Nf6 6. Bc4 d5 7. exd5 Bd6 8. 0-0 (The Rice Gambit where, instead of the normal 8.d4, White offers the sacrifice of the knight on e5 in order to get his king to safety and prepare a rook to join the attack against Black's underdeveloped position). The move 8...g3 is called the Bernstein Defense by the tournament book.

     Born into a Jewish family, he lived in New York and was good enough to have won three consecutive New York State Championships (1920, 1921 and 1922); he also shared 1st with Herman Steiner in 1929, but lost on tiebreaks. Bernstein tied for 8-9th at New York 1913 (Rice tournament, Capablanca won), tied for 5-6th at New York 1915 (Capablanca won), tied for 7-8th at New York 1916 (Rice tournament, Capablanca won), and lost a match to Abraham Kupchik (1.5 : 3.5) at New York 1916.
     After World War I, he tied for 3-6th at New York 1922 (Edward Lasker won), took 13th at Carlsbad (Karlovy Vary) 1923, and tied for 7-10th at Pasadena 1932 (Alexander Alekhine won).
     In one of Edward Winter's articles the strong New York master Sidney Bernstein described meeting Bernstein (no relation) in New York City in the Spring of 1987 and described him as "very old" but still good enough to defeat him (Sidney) easily in offhand games. Arnold Denker described Jacob Bernstein's establishment, the Stuyvesant Chess Club of the 1930's, as being filled with people "who would rather play chess than eat." 

Street view today
     Denker said there was no restriction on smoke or noise and English was rarely heard; it was mostly Russian, Yiddish or Polish. The club was a long room in a brownstone building with chess tables at the front, then card tables and all the way at the rear was a small kitchen run by Bernstein's wife. Denker described the place as a "gambling parlor" which Bernstein ran despite the fact that his wife had numerous relatives on the police force. Things hadn't changed when Sidney visited the club because he also described it as a gambling parlor.
     Jacob Bernstein, known to his friends as Yankele, was described by Denker as being completely bald, short, fat and greasy looking with a neck like wrestler. That description does not fit the photo I discovered on Edward Winter's outstanding history site. 


     According to Winter, the photo is taken from the Carlsbad, 1923 tournament book and while many sources identify the player as Ossip Bernstein, it is actually Jacob. Winter also has a photo taken in New York, in 1915 showing Jacob sitting across from Frank Marshall. He looks like the same guy. Apparently by the time Denker met him, Bernstein's appearance had changed a lot or else Denker's 84 year old memory was fuzzy by the time he wrote, The Bobby Fischer I Knew.  By the way, Denker's book is great reading. It has over 300 games and positions, many never before published, and Larry Evans described it best when he wrote, "So many people in these pages...seems to emerge from the walls to take one last bow." The price has gone up $5 since I bought my copy, but I would spend $25 for it if I had too because I enjoyed it that much.


     I was, as usual, going to present one of Bernstein's games but decided not to because to be honest, all the ones I played over were boring affairs with little in the way of spectacular play. So, I decided not to bother.

Saturday, January 24, 2015

GM Ben Finegold Sez...

Finegold offers some humorous but very good practical advice in the form of New Year's resolutions on the USCF site. Some of the comments offer good advice, too, so be sure to read them also.

1-I won't get into time trouble
2-I won't move quickly when I think my opponent has just blundered
3-I will play the same regardless of my opponent's rating
4-I will stop taking draws against better players when I have a good position.
5-I will try a new opening, and not play the same stale stuff I have played for 25 years

Read the complete article...

Friday, January 23, 2015

Black Mamba Engine

     Ranked 8th on the CEGT 40 moves in 120 minutes rating list, BlackMamba is a multi-core engine for Windows (32 and 64bit), Linux (32 and 64bit) and Android.
     According to one person posting on one of the forums, this engine makes sacrifices like a human player. I ran a short G5 match between Black Mamba and Houdini 1.5 with a +1 -1 =2 result.
     In the game that Black Mamba won, thngs looked to be equal for the first 54 moves then Houdini made a positional error that allowed BM to trade down into a R and minor piece ending which was eventually won in 93 moves.
     Houdini's win was a game in which the position was equal when a Q and B ending was reached at move 35. BM was a Pawn up, but had a B that was miserably placed, being blocked in by its own P's and K. That's when it made a tactical mistake that returned the extra P and still left it with a very bad B. By move 65 the game was down to a B and P ending with an easy win for Houdini. The draws were pretty uneventful. Black Mamba Home page.

Thursday, January 22, 2015

Jewish Chess Players


While I was doing some research I stumbled across this site that has some nice photos and brief bios of Jewish players, including not only the well-known but a lot of lesser known players.  The information seems to come from Wikipedia, but the nice thing about the site is the photos of the players and the information on a lot of players (who are not listed in any particular order) is gathered in one place. It's main value is that it makes interesting browsing.

Wednesday, January 21, 2015

Arthur D. Wang

     Arthur Wang (b. June, 1942), a master back in the days when masters were rare, passed away on Monday, December 12, 2011 after a prolonged 18 month battle with esophageal cancer
     Wang was born in Chung-king, China and came to the United States in 1946 with his mother and older brother, Harvey. His father stayed behind as head of security for Chiang Kai-shek but did not survive the year. Things were difficult for Wang's mother who had lost everything but a small inheritance. They ended up in Berkeley, California where he grew up. He graduated from Berkeley High School at 16 and earned his BS and MBA from UC Berkeley. Wang enlisted in the Army in 1962, got married and started a family with his first wife and mother of his three children. He returned to Vietnam in 1975 to evacuate 19 family members one day prior to the unmitigated disaster known as the Fall of Saigon.
     Wang took up residence in Palo Alto, California in 1978. After his time in the Army he worked at the Radiation Lab in Berkeley on the mapping of the bubble chamber trails of subatomic particles and his wife had started an import business from Vietnam and his chess activity took a back seat to earning a living and other interests.
     He learned to play chess at a Koltanowski chess festival in Sonoma, California and soon became a regular at the Berkeley YMCA, and later at the Mechanics' Institute of San Francisco. Wang played in the 1957 US Junior (won by Bobby Fischer) and later won the California Junior Championship in 1960. The 1960 Mechanics' Institute tournament was his best when he tied for 1st with William Addison, who later became an IM and one of the leading players in the US.
     Wang returned to chess after his stint in the Army as a member of the famous Castle Club in the late 1960s; he won or was co-champion of the club nine times.
     Besides chess his hobbies were golf, pool, archery, knife and ax throwing, and shooting.  Of all his hobbies golf was his favorite right behind chess, but unlike chess, in golf he was truly a duffer. He was also known for his willingness to bet on sporting events and just about anything else, including which elevator would arrive first.
     Wang was a financial executive and worked for Price, Waterhouse, Coopers and worked in banking and high tech companies like Vitelic and SanDisk. He met his wife Katherine in Singapore and they were married in February 1979 and enjoyed travelling throughout Asia, Europe, Argentina and the U.S. He also lived in various countries including the Philippines, Hong Kong, Singapore, Malaysia, and Thailand.
     His style was positional and he leaned towards playing endings; he was a mini-Smyslov.


Tuesday, January 20, 2015

Jan Foltys

 
    Jan Foltys (13 October 1908 – 11 March 1952) was a Czech International Master. Unfortunately his life was cut far too short, only 44 years, by leukemia.

Some results:
1933 - tied for 8-12th in the Czech championship and tied for 5-7th in Moravska Ostrava
1935 - tied for 5-7th in Luhačovice
1936 - 3rd in Poděbrady (14th Czech championship); the event was won by Salo Flohr
1937 - 4th in Margate; tied for 3rd-4th in Prague; tied for 2nd-4th in Rogaška Slatina; tied for 9-10th in Jurata (4th Polish Championship); the event was won by Savielly Tartakower.
1938 - 3rd in Prague (Czech championship); tied for 10-12th in Łódź; finished 11th in Ljubljana
1939 - 7th in Stuttgart (1st European Tournament); the event was won by Efim Bogoljubow.

Foltys played first board for Czechoslovakia at 3rd unofficial Chess Olympiad in Munich in 1936 (+7 –1 =11), at second board at the 7th Chess Olympiad in Stockholm in 1937 (+7 –2 =9), and at second board at the 8th Chess Olympiad in Buenos Aires in 1939 (+8 –3 =5). Altogether in these three events, in 53 games, he scored (+22 -6 =25), for 65.1 per cent.

During World War II, Foltys played in several strong tournaments.
1940 - won in Rakovnik
1941 - won ahead of József Szily and Ludovit Potuček in Trenčianske Teplice. Also in 1941 he took 7th in the Munich tournament; the event was won by Gösta Stoltz; he drew a match (6-6) with Karel Opočenský in Prague.
1942 - tied for 3rd-5th with Efim Bogoljubow and Kurt Richter, behind Alexander Alekhine, and Paul Keres, in Munich. Also, in December 1942, he took 3rd behind Alekhine and Klaus Junge in Prague (the Duras Jubileé Tournament).
1943 - tied for 4-5th in Prague; the event was won by Alekhine. 5th in Salzburg; the event was won by Keres and Alekhine. tied for 1st-2nd with František Zíta in Prague. 2nd, behind Čeněk Kottnauer in Zlín.
1944 - 4th in Brno

After the war, Foltys participated in many tournaments and team matches.
1946 - tied for 4-5th in Prague. The event was won by Miguel Najdorf. In 1946, he took 3rd, behind Luděk Pachman and Miroslav Katětov, in Ostrava, the Czech Champonship.
1948 - Foltys had his best tournament result at Karlovy Vary / Mariánské Lázně in 1948. In the same year, he took 3rd in Budapest.
1949 - tied for 1st with Stojan Puc in Vienna; tied for 4-7th in Venice; 6th in Trenčianske Teplice.
1950 - 7th in Szczawno Zdrój. 13th in Amsterdam. Awarded the International Master title.

He qualified in Mariánské Lázně in 1951 for the Interzonal of Stockholm 1952, but died at Ostrava in 1952 before it took place. In the following game, the final position is quite picturesque.

Saturday, January 17, 2015

Problem by the Sarychev Brothers

     I am not into chess problems very much but when I saw this one the other day I found it quite intriguing. It's a well known problem by Alexander Vasilievich Sarychev (1909 – 1986) who, along with his brother Kirill Sarychev (1909 – 1950), composed mostly endgame studies. I was also curious to see how various engines did on solving this problem. Gull, Critter Rybka, Fritz, Stockfish and Komodo all found the key move instantly. The problem reminded me of Reti's famous study shown HERE.
     It should have because Reti's study inspired a host of other problemist to imitate his idea and in 1928 the Sarychev brothers came up with their version which is no less intriguing. White catches the Pawn by starting to run away from it.

Enjoy Some Pickin' by Uncle Dave Macon


Thursday, January 15, 2015

Harlow B. Daly




    A reader suggested that I do a post on Harlow B. Daly, so here it is. Unfortunately I could not find a lot, but what I did find suggests he was an incredible person. I remember Daly's name cropping up from time to time in Chess Review and Chess Life, but because it was always in relation to tournaments in New England, I never paid much attention to him. It turns out he was a fascinating person.  While typing this brief post, I kept repeating myself using words like remarkable and amazing.
     Daly was relatively unknown outside of his native New England and his career spanned eight decades from Harry N. Pillsbury to Bobby Fischer. During his career he played in simultaneous exhibitions against Alekhine, Lasker, Pillsbury, Mieses, Marshall, Fine, Torre and Dake.
     Harlow Bussey Daly was born in Dorchester, Massachusetts on December 2, 1883 and is likely the oldest person to ever win a state chess championship. He played chess for 75 years (1900 to 1974). He won the championships of Massachusetts, New Hampshire, Vermont, and Maine (9 times). He competed in 280 tournaments and matches, not counting correspondence events.
     Daly holds two records in Maine chess that still stand to this day; he won seven consecutive Maine State Championship titles from 1959 to 1965. That made him 76 years old when he won the first time, but he wasn't done! In 1969 he won the Championship of Maine at age 86. That's hard to fathom but he still wasn't finished; he tied for 1st in 1970 (with Master Stanley Elowich) and was 2nd in 1971 and 1972.
     Daly played in the New England Open every year from 1908 (when he won it) to 1971; a stretch of 63 years. He won the Massachusetts State Championship in 1940 and 1942. As remarkable as those achievements were Daly was still successfully playing chess in his early 90s.
     At 90, in 1973, he won a New Hampshire Open tournament with a perfect 5-0 score. In 1975, he was designated Master Emeritus by the USCF. He died on July 8, 1979 in Framington, Massachusetts at the age of 95 and was buried at the Mount Pleasant Cemetery in North Berwick Maine.

     In 1975 New England Master Harry Lyman authored a 40 page booklet titled 75 Years of Affection for Chess : A tribute to Harlow B. Daly. Documents of City of Boston for 1910 showed Daly as being employed as a city Clerk at a salary of circa $30,000 year in today's dollars. He lived at 7 Butler Street; the area today consists of apartment buildings.     
     Here's a game from the book: It's unusual to feature a game a player lost, but while looking at some of his games I found this one (which appears in the booklet on Daly) which is simply too amazing to not post!
 


Wednesday, January 14, 2015

How Isaac Kashdan Lost the 1942 US Championship




    Like Reuben Fine, Kashdan, one of the strongest US players ever, never won the US Championship. In 1942 he came close.
     After a lot of controversy the whole tournament hinged on a single move, but it was not a move by Kashdan. It was a move by 6th place finisher, I.A. Horowitz.
     The most controversial US championship ever was the one held in 1942. It began on April 10, 1942, five months after Pearl Harbor and there was doubt that there would be a U.S. championship for several years. The USCF had sent out an announcement in January cancelling the championship because "The United States Government has issued a call for an all-out struggle in a war which has been thrust upon us," adding, "Our way of life is in great peril ... [and] the present time is not propitious for holding a championship tournament.” In his Chess Review magazine Al Horowitz was against the cancellation, pointing out that Washington had encouraged the continuation of professional sports and that other nations at war - such as Great Britain - had continued the traditions of chess despite the fighting. The USCF relented and the top players agreed to forego appearance fees and guarantees of prize money agreeing to play for modest prizes.
     The result was that the tournament was not a very strong one, several of the stronger players being unavailable for various reasons. Actually, out of the 16 players there were only seven real contenders: Reshevsky, Kashdan, Denker, Steiner, Pinkus, Horowitz and Seidman.
     One of the biggest disappointments of Kashdan's career was his failure to win the US Championship and the 1942 tournament was probably the bitterest of all. This tournament was a race between Kashdan (+11 -1 =3) and Reshevky (+10 -0 =5). Kashdan would have been U.S. champion in 1942, but for two unfortunate incidents over which he had no control.
     The first happened in the 6th round when the tournament director, the infamous L. Walter Stephens, incorrectly forfeited Denker after Reshevsky exceeded the time limit. Reshevsky had been winning but one move before the time control he threw it away. Denker, also in time trouble, played the drawing move and when he punched the clock, Reshevsky's flag fell. Stephens, standing behind the clock, picked it up and turned it around so that the clocks were facing opposite sides and then declared Denker forfeited. Despite howls of protest from Denker and the spectators, Stephens refused to change his decision. When asked, Reshevsky replied, “It’s not my decision.”
     Reshevsky opened up a lead over Kashdan when Kashdan overlooked a brilliant queen sacrifice by Hreman Steiner and lost. But in the next round Reshevsky could only draw against the last place finisher, a minor master from Chicago by the name of Herman Halhbohm.
     After his last round game finished Kashdan had a 12.5 – 2.5 score and he sat down to watch the Reshevsky-Horowitz game. Reshevsky was at 12 points and so the result of that game was critical. Horowitz outplayed Reshevsky and adjourned two pawns up.
     After Denker's 45th move Kashdan observed that to the spectators it looked to be all over, but opposite colored bishops and Reshevsky's better placed king offered drawing chances. Kashdan later wrote, “I refuse congratulations, wondering what it will be like to be champion .... It has been three long weeks. I am thinking back to 1934 when I challenged Frank Marshall to a match for the American championship and the number of times I have tried for the title since. This is my best. Just a few good moves, friend Horowitz .... "
     Indeed, Horowitz made good use of his extra material for the next several moves. But then came Horowitz' 58th move. It allowed Reshevsky to draw and Reshevsky had another last-round miracle that resulted in co-champions for the first time in the history of the US Championship.
     The result was a playoff. The playoff was a 14-game match which began in October and was held at US Army camps for the benefit of the troops. The match seesawed back and forth for the first four games but when the match returned to New York City for the fifth game Reshevsky took the lead and never relinquished it, finishing +6 -2 =3. Here's the Reshevsky vs. Horowitz game.



Tuesday, January 13, 2015

Mickey Mouse Equipment


What I have
    I have been analyzing several games of late using engines and keep running into positions where different engines are giving way different evaluations. Then when you actually start playing through the lines things get even more confusing because the numeric values are all over the place. 
     These games have mostly been annotated GM games from books, and when a GM says the position favors one side, or maybe even is winning, but the engines show only a nominal advantage or perhaps even prefers another move, what do you do?
     I was playing over a Zvjaginsev vs. Khalifman game from Moscow 2005 and had Khalifman played 27...f6 things would have been equal, but analysis with several engines proved to be pretty murky.
     I have a couple of correspondence games going that have been very difficult to analyze. In one game as black I played the K-Indian against a FIDE IM and gradually drifted into what appears to be a lost game without making any obvious mistakes. Of course it's also pretty well-known engines don't evaluate those types of positions very well, so I should have avoided it.
What I need
     Another game was dead equal for 30 moves and when my opponent played Stockfish's initially recommended move it turned out that two (!) moves later the evaluation jumped to a significant 1-1/3 Pawn advantage in my favor.
     In another game, I accidently played the wrong move at move 4 and the position was evaluated by Komodo 8 as one Pawn in my opponent's favor. After 50 more moves we had a position that the engines claimed were significantly in his favor, but as confirmed by the Shredder endgame database, was drawn.  In yet another game against an ICCF Senior IM the engines said my advantage was nearly a Pawn, but in the end, the game was only a draw.
     How do you explain this? I can't because I simply am not good enough to know when the engines are wrong. Their evaluation scores are an aggregate of various factors (material, space, two-bishops, open files, weak Pawns, etc.) so all factors considered, the “score” is simply an approximation of the position. It has been pointed out that Stockfish's evaluations can be erratic; in some positions it shows the same score for a long time then all of a sudden it may make a big jump. It makes good moves, but sometimes the evaluations can be whacked out. That's why you need another engine to keep an eye on SF.
     Tactically Houdini (I only have H2) is still the "go-to" engine. I run it for Shootouts when I want a quick opinion on possible outcomes. That is, if move A results in +1 -1 =1 and move B results in +0 -2 =1, I suspect move A is probably the better of the two. Supposedly Rybka is pretty good tactically, but I don't use it.
     Komodo seems to be middle of the road in that it calculates tactics well, is good in semi-closed positions and plays really good in the ending.
     Anyway, I have also noticed another strange thing...searching at higher depths doesn't necessarily mean a better evaluation because the engine may be evaluating a bad line. Just because the engine says it has searched to a 30-ply depth does NOT mean it has looked at EVERY move. What it has done is, it ignored branches that didn't look promising.  Sometimes another engine may find a win in a line another engine pruned.
     What all this means is that analyzing games for fun and trying to ferret out the best move in a GM game can be challenging, if not impossible. For example, in the Zvjaginsev vs. Khalifman game at move 31 Komodo 8 evaluates move 31.Nh6 at 0.82 while 31.Rxe3 (the move played) is evaluated 0.00.

Is it really possible that a 2600+ GM did not see the difference between the two moves or are the engines missing something? I could probably figure it out IF I had a powerful enough computer and enough gumption to spend hours analyzing, but I don't. That's why I probably would not do too well if I enter the upcoming LSS World Championship Preliminaries that I was recently informed I qualified for. A piddly little laptop and no gumption won't get you very far in correspondence chess.


Monday, January 12, 2015

What a Disappointment...

...this game must have been for the relatively unknown Singapore master. He had the former world champion on the ropes, but couldn't deliver the knockout punch. The game is annotated in part in Soltis's book, The Inner game of Chess, How to Calculate and Win. It's not my intention to review the book here. It's been called a classic and it's been called poorly written. The book came out in 1994 and computers were able to play chess fairly well but the book contains quite a few analytical errors, so it's obvious Soltis didn't error check his analysis. Still, the book is a fascinating insight into GM thinking and I think it's still a worthwhile purchase.  If you take your time to go over the games, especially with an engine, it will at least make you think.
     The following game is a case in point. Soltis's analysis was really bad. But that aside, you really have to feel for Tan; he played extremely well, got his opponent, one of the unappreciated greats of chess, on the ropes but then lost the thread of the game and just couldn't put him away.  It's obvious that a lot of Tan's errors were due to time pressure because he finally overstepped the time limit in a slightly inferior position. According to Komodo 8, which was running for about an hour on the final position while I was out blowing snow, black's advantage is a little over half a Pawn. I think black's position was good enough that Smyslov probably would have been able to squeeze out a win. I can empathize with Tan. Years ago I had a 2500+ IM busted by move 12 in a weekender, but couldn't put him away. After much dalliance, I blundered a couple of times and lost!