Revisionist Chess History

In my previous post I presented Some Numbers for 'Pawn Sacrifice'. Here's a short conversation on one of the film's basic premises.

Tobey Maguire as Chess Player Bobby Fischer in 'Pawn Sacrifice' (4:19) • 'The Victoria To Uyen Show' (Vietnamese subtitles)

The interview starts,

Q: 'I didn't know that Bobby Fischer had this mental illness, that he suffered -- because he was such a great chess player.' A: 'It's fascinating that somebody can be so exceptional at something, particularly a game of strategy that seems to require a sound mind that can reason well, but yet be stricken with seeming-like mental illness. It seems he was paranoid, delusional.'

I don't recall anyone saying that about Fischer until long after he became World Champion, long after the events in the film.

Some Numbers for 'Pawn Sacrifice'

The movie 'Pawn Sacrifice' -- some folks call it a 'biopic' -- has been out for over a month now. How is it doing at the box office?

Source: boxofficemojo.com/movies/id=pawnsacrifice

Let's do some guesstimates: domestic gross $2.410.166 at $10 per ticket gives around 240.000 keen chess players in the USA. (Who else would want to see it at the first opportunity? Perhaps their significant others, but that cancels out the players who haven't seen it yet.) So far I've featured the film in one post...

• 2015-09-18: Fischer Was the Donald Trump of 1972?!

...while the Jim West On Chess blog has been somewhat more active in following its progress:-

• 2010-04-20: Preview of "Pawn Sacrifice" Script
• 2012-10-29: Shopping "Pawn Sacrifice"
• 2013-08-31: "Pawn Sacrifice" into Production This Year
• 2013-11-15: Conrad Pla Joins "Pawn Sacrifice" Cast
• 2014-07-24: "Pawn Sacrifice" at 2014 TIFF
• 2014-09-05: World Premiere of "Pawn Sacrifice" at TIFF
• 2014-09-14: Distributor and Premiere for "Pawn Sacrifice"
• 2015-02-05: "Pawn Sacrifice" Release Date 9/18/2015
• 2015-02-13: "Pawn Sacrifice" at Bleecker Street Welcome
• 2015-04-15: "Pawn Sacrifice" Wallpaper
• 2014-05-11: Score for Film "Pawn Sacrifice"
• 2015-05-23: "Pawn Sacrifice" Poster
• 2015-05-28: "Pawn Sacrifice" Trailer
• 2015-06-03: Reviews of "Pawn Sacrifice" Trailer
• 2015-07-08: Montreal and Brooklyn in "Pawn Sacrifice"
• 2015-07-20: "Pawn Sacrifice" on Facebook
• 2015-07-30: "Pawn Sacrifice" Motion Poster
• 2015-08-12: "Pawn Sacrifice" Clip
• 2015-08-16: Images from "Pawn Sacrifice"
• 2015-08-19: Maguire as Fischer in "Pawn Sacrifice"
• 2015-08-20: "Pawn Sacrifice" Featurette
• 2015-08-23: Private Showing of "Pawn Sacrifice"
• 2015-08-29: Facts Sacrificed in "Pawn Sacrifice"
• 2015-08-31: e-mail from Ginny Hoffmann
• 2015-09-06: "Pawn Sacrifice" Soundtrack to be Released
• 2015-09-11: "WSJ" Review of "Pawn Sacrifice"
• 2015-09-13: "LA Times" Review of "Pawn Sacrifice"
• 2015-09-21: GM Soltis Discusses "Pawn Sacrifice" on NPR
• 2015-10-09: Reviews of "Pawn Sacrifice"
• 2015-10-17: "Pawn Sacrifice" in "The New Yorker"
• 2015-10-23: "Pawn Sacrifice" in "The Cornell Daily Sun"
• 2015-10-25: "Pawn Sacrifice" in "The Harvard Crimson"

I count 32 JWOC posts -- the number of pieces at the start of a chess game -- although I might have missed a few posts. If you want more reviews, see Pawn Sacrifice - Movie Reviews on RottenTomatoes.com; they give the move a 71% fresh rating. Can't sniff at that!

[Disclaimer: Living in Belgium, I haven't seen the flick yet. Which European TV channel will air it first? I might have to wait until it turns up on Netflix.]

New Stats for M-W.com

Over the summer, the statistics package for my domain m-w.com blew up on me. I had been using the same package since I set up the site in 1999 and I think it just became old and obsolete. After filing an error report to technical support for the third time within a few months -- the stats were not updating -- they deleted all trace of the old package. I took the hint and installed a new package, called Urchin.

The last time I wrote about site stats was earlier this year in Photos of February. Like most of my posts on the subject, it was based on my own analysis of the site's log file. Could Urchin duplicate what I had been doing myself? I waited until enough time had passed to collect a few months of log data, then looked at Urchin for the month of September. A summary is shown below.

Report: Status and Errors - mark-weeks.com

The table gives a count of requests to the server and how they were resolved. For me, the most urgent are the '404: Not Found' errors. A few years ago I analyzed these in Most 'HTTP 404' Are External Errors. The conclusions I derived then still hold today, with one exception that I'll look at as soon as I've finished this post.

Chess Engines : FishCooking

In my previous post in this series, Chess Engines : Fishtest, I asked, 'How does this work in practice?' A page on Stockfishchess.org, Get Involved - Stockfish - Open Source Chess Engine -- 'Whether you are a programming wizard or just a fan, there's something you can do to help make Stockfish even better' -- explains its three-pronged approach:-

• Volunteer Your Computer
• Write Code
• Discuss

'Write Code' points to official-stockfish/Stockfish on Github.com. 'Discuss' points to FishCooking on Google Groups:-

This is a discussion group for developers and testers of Stockfish chess engine.

If you're interested in chess engines, you're probably aware of the ongoing competition TCEC Season 8. A few months ago I wrote a post giving Preliminary Info. The Stockfish entry encountered a glitch a few weeks into the event, described in Press release regarding the Stockfish case in TCEC Stage 3:-

TCEC Press release, 11 October 2015 : Stockfish has submitted for Stage 3 of TCEC a not fully stable version, which contains a few bugs related to the new "lazy-smp" code. This has prevented the engine to finish two of the four games played so far in the event, instead losing these games on time.

The phrase 'Lazy SMP' didn't mean anything to me, so I looked on chessprogramming.wikispaces.com:-

Parallel Search • Parallel Search, also known as Multithreaded Search or SMP Search, is a way to increase search speed by using additional processors. [...] Shared Hash Table : This technique is a very simple approach to SMP. [...] Lazy SMP : Recent improvements [...]

Got it, thanks. Lazy SMP is a table technique to implement parallel search and a new version went awry during the TCEC event. The details can be found in the FishCooking forum, e.g.

• 6 October: Binary for TCEC w/ Lazy SMP • 'If we are going to use lazy SMP in the next TCEC stage...', and
• 9 October: TCEC ttime loss vs Gull in drawn ending • 'I warned about time losses. But I also recommended we use the lazy SMP...'

The entire sequence of events is documented on that forum. If you're interested in that sort of thing (aren't we all?), it provides an advanced education in creating modern chess engines and in open source software development.

One Painting, Three Versions

For this ongoing series titled Top eBay Chess Items by Price, I don't usually feature unsold items, but sometimes they are so compelling that I shuffle my priorities. I could have posted a follow-up on the sort of Fischer items featured in Mushroom Harvest, or picked from a handful of other items on my short list.

The item pictured below was titled 'Jean Henri Marlet "19th game of chess match" Staunton - Saint-Amant, oil / canvas', and was offered for US $17.250, 'Buy It Now'. The auction eventually ended with the statement, 'This listing was ended by the seller because the item is no longer available.'

The item's description started,

The author of this composition - well-known French artist of the 1st half of the 19th century Jean Henri Marlet - probably replicated it few other times. The variation offered in 2006 at Sotheby's London differs from "ours" by a single detail, namely by the absence of the chandelier hanging from the ceiling. There exists also a lithograph by Alexandre Laemlein (1812-1871), which at some point provoked a somewhat of a scandal.

The rest of the description, plus photos showing details of the painting, are on the seller's web site, Wilnitsky.com: Jean Henri Marlet "19th game of chess match" Staunton - Saint-Amant (16th December 1843), oil on canvas. The story of the 'scandal' was copied from Chesshistory.com, Pictures of Howard Staunton, which offers a second, etched version of the painting and a clue to locating a third version, which appears to be the original.

In C.N. 5259 [should be 4259] Gene Gnandt (Houston, TX, USA) raised the subject of the 1843 illustration of Staunton v Saint Amant, which has been widely published (e.g. as a supplement to the November 1911 issue of La Stratégie). Noting that a key was given on pages 325-326 of volume two of Geschichte und Litteratur des Schachspiels by A. van der Linde (Berlin, 1874), our correspondent added numbers in the reproduction below: [...] For further details about the painting, and a reference to a slightly different key, see C.N. 5395, which provides a link to information we received from Etienne Cornil (Brussels).

The third version (2006 Sotheby's, 'absence of the chandelier') differs from the eBay version by far more than a 'single detail'. All three versions can also be located by an image search on the Staunton - Saint-Amant Matches.

The Three Bishops

'The TIE fighter pilot utilizes a Bishop.' Wikipedia explains,

TIE fighters are fictional starfighters in the Star Wars universe. Propelled by twin ion engines (hence the TIE acronym), TIE fighters are fast, fragile starfighters produced by Sienar Fleet Systems for the Galactic Empire. • TIE fighter

I would have liked the photo even without knowing that.

Star Wars Extravaganza © Flickr user Skokie Public Library under Creative Commons.

I count two other Black Bishops on the board. I also count eight Black pieces plus the piece the fighter pilot is holding, which does indeed look like the other Bishops. Maybe it's bughouse.

Karpov at Disney

In my previous post, Dingo and Mickey Play Chess, I wrote, 'The Disney company has long been a supporter of chess.' When I read this a second time, I wondered if I could back up the statement with facts.

My page Karpov's Tournament, Match, and Exhibition Record 1985+ ('Last updated 2001-05-04'?!), mentions three Disney events -- 1993 EuroDisney; 1994 Simul, Disney; and 1998 Disneyland Paris, Marne-la-Vallee -- but I had never looked into them any further. I found a report for the 1993 event in Europe Echecs, February 1994, written by Christophe Guéneau, who is also credited for the photo of Etienne Bacrot and GM Karpov shown below.

I couldn't find a report for the '1994' event. A Chess Life report for the 1998 event included an interview with Pierre Sissmann of Disney, who mentioned, 'It's the fifth time we've organized a big chess event'.

The December 1993 event was the European Youth Rapidplay Championship (U12 & U14), a December 1995 Disney event had the same title & categories plus a Karpov simul, and the November 1998 event was the World Youth Rapidplay Championship (U12 & U14). The various youth championships are often documented haphazardly, depending on which countries can claim the winners, so it's not surprising that I couldn't find all of the events quickly.

Dingo and Mickey Play Chess

We've all been there before. You're locked in a tense game of chess when all of a sudden a frog jumps on the board and knocks the pieces over. Then you can't reconstruct the position.

From Minnie - Mes Belles Histoires (Pi Kids, 2013)

Reading the book to my two-year-old granddaughter, we found this image in the story 'Une Journée à Rebondissements!' ('A Day of Twists and Turns', or something like that). I especially like the two pieces -- King and Queen? -- with mouse ears. My granddaughter especially likes to name the characters. Shown here are Dingo et Mickey.

The Disney company has long been a supporter of chess. See also Chess at Disney's Magic Kingdom, on this blog.

Chess Engines : Fishtest

In this weekly series on Modern Chess Engines, last seen in Bitboards, I've covered most of the topics that caught my eye in the original video. One topic, specific to Stockfish, took up the last third of the video. It started,

Unit tests: It's hard to unit test a chess engine. You can certainly test that the moves it generate are valid or that it doesn't do terrible moves, but you can't test strategy because you don't know what the corect move is yourself. So we say 'Goodbye!' to unit tests and instead we have the Fishtest framework.

Wikipedia explains,

Stockfish • Since 2013, Stockfish is being developed using a distributed testing framework named Fishtest, where volunteers are able to donate CPU time for testing improvements to the program. Changes to game-playing code are accepted or rejected based on results of playing of tens of thousands of games on the framework against an older version of the program, using sequential probability ratio testing. Tests on the framework are verified using the chi-squared test, and only if the resulting p-value is not statistically significant, the test is deemed reliable.

As of April 2015, the framework has used a total of more than 250 years of CPU time to play more than 165 million chess games. After the inception of Fishtest, Stockfish incurred an explosive growth of 120 elo points in just 12 months, propelling it to the top of all major rating lists.

The italics are mine. From chessprogramming.wikispaces.com:-

Stockfish Testing Framework • Fishtest is a web application written by Gary Linscott mainly in Python under the Pyramid Application Development Framework, to distribute games across different machines to reduce the test latency and increment throughput. Started in early 2013 with Stockfish 3.0, Fishtest has hundreds of contributors, as of May 2014, 744 testers and 52 developers active in testing ideas and tweaks, to make Stockfish the strongest open source or even chess program of the world.

How does this work in practice? I!ll look at that in my next post in this series.

Chess Curriculum - FIDE I

After Chess Curriculum - Susan Polgar, the next candidate to be reviewed in Chess Curriculum Inventory (June 2015) is the FIDE Chess Curriculum.

That initial post on the FIDE program offered a couple of Fide.com links to find the FIDE material and listed two resources by Dr. Olgun Kulac. Since then the FIDE material has expanded. Along with the logo shown on the left, the FIDE CIS commission has reorganized its recommendations into Class Materials and Work Books.

We have been assembling a set of royalty-free materials that can be used for teaching chess in class (and pre-school). [...] We have now reorganized the access to them to make it much easier for you to find the material and to download it.

The material is organized by age category -- 4-6 (available in the autumn), 6-7, 7-9, and 9+ -- where the Kulac documents fall in the age 7-9 category. Although planning to review the Kulac material for this post, I was sidetracked by the new documents. Here are the new titles in the same format I used for the 'Inventory' post.

Age 6-7: Chess: The First Year of Study • Elvira Umanskaja, Ekaterina Volkova • 117 pages • wc_book-en.pdf --and-- Chess: The First Year of Study - Workbook • [same authors listed in Russian] • 29 pages • wc_workbook-en.pdf

Age 9+: Welcome to Planet Chess! • [no author mentioned] • 52 pages • planet_chess_en_2014.pdf

I'll come back to these documents for my next post in this series.

World Cup Trailer

The story of the recently completed World Cup told in less than four minutes.

Baku World Chess Cup 2015 (3:40) • 'I declare that the World Cup 2015 is open.'

One of seven promotional videos on Youtube channel BakuWorldChessCup2015.

World Championship Stalwarts

While working on 2015 World Cup Players on my World Championship blog, I added the 128 players from the recent Baku World Cup to the World Championship : Index of players. I started to ask myself a few questions -- How many events does the index of players include? How many players? Which players participated in the most events? -- and so on.

Today I collected the data from that index and loaded it into a database to do some simple queries. I discovered that 803 players have participated in 134 events. A breakdown is shown in the following tables.

The table on the left counts the number of players that participated a certain number of times in World Championship events. For example, one player participated in 22 events and 398 players have participated in a single event. The table on the right shows which players participated in the most events. GM Korchnoi heads the list.

What about those 398 players who have participated in a single event? I count 36 players who appeared only in the 2015 World Cup, and 25 players only in the 2013 World Cup. That's not too surprising, since some of these players will undoubtedly appear in future World Cups.

Somewhat more surprising are the 24 players who participated only in the 2001-02 FIDE Knockout Matches or the 21 players from the 2004 FIDE Knockout Matches. It's increasingly unlikely that any of these players will appear again in a World Championship event.

As for historical tournaments, 11 of the 16 players in the 1851 London Tournament never competed in another event -- there weren't many events at that time. More surprising are the 10 players (out of 24) from the 1964 Amsterdam Interzonal Tournament who never competed again. Why so many from that one tournament?

The Rybka - ICGA Ethics Judgement

After yesterday's post Chess Engines : Bitboards touched on 'The Rybka Affair', I started wondering what had become of the matter. First, here's a summary of previous posts on this blog.

The Rybka Affair: An Official Reaction (January 2012) • 'On the Rybka disqualification from the World Computer Chess Championships'

Feller, Rybka, Arbiters, and More (October 2012) • FIDE Ethics Commission: 'Case 2/2012: "Rybka and ICGA" (complaint by Mr Vas Rajlich and Mr Chris Whittington against the International Computer Games Association ("ICGA")) Procedural decision (preliminary request of additional information).'

Ethics and Cheating (December 2013) • 'Case 2/2012: "Rybka and ICGA" [...] concerning an assumed violation of par. 2.2.3 of the FIDE Code of Ethics has to be considered as receivable'

The original ICGA action dates back to June 2011, more than four years ago. I found a couple of relevant posts on RybkaForum.net. The first was from the time the case was accepted:-

FIDE Case 2/2012 “Rybka and ICGA” • 'From the FIDE Code of Ethics: 2.2.3 Organizers, tournament directors, arbiters or other officials who fail to perform their functions in an impartial and responsible manner.' (November 2013)

The second was from six months ago:-

Complaint to FIDE Ethics Commission (April 2015) • 'The FIDE decision was made in 2014. It was delivered recently. We're not allowed to publish the judgement as a whole, but we may quote from it. The complaint is attached.'

One quote contains a (partial?) summary of the judgement

The EC [Ethics Commission] unanimously rules that:
- Otherwise, by imposing a lifetime ban as a sanction against Mr Rajlich, in absence of a clear statutory basis and without sufficient procedural guarantees for Mr Rajlich, the ICGA did not act in accordance with FIDE rules, this way violating par. 2.2 and 2.2.10 of the FIDE Code of Ethics.
- ICGA has to be sanctioned with a warning and has to be invited to modify their statutes in accordance with FIDE principles and rules.

The word 'otherwise' in the first bullet makes me think that something is missing. More discussion can be found at FIDE Rules on ICGA - Rybka controversy (April 2015; Open-chess.org). I can't imagine that anyone is satisfied with this outcome.

Chess Engines : Bitboards

In this series of posts on Modern Chess Engines, of which the most recent was LMR (Late Move Reductions), the emphasis has been on software, i.e. algorithms. The engines are as strong as they are because (1) their static evaluations of specific positions are amazingly accurate, and (2) they can focus on the variations that are the most critical.

Not all of the engines' strength can be attributed to software. In parallel with algorithmic discoveries, computer hardware has also been advancing rapidly. Not only are processors smaller and faster, they are also more versatile.

A few years ago I was impressed by the diagram on the left. It shows the increase in Elo by chess engines over the 20 years 1990-2010. A larger diagram, including a legend for the individual lines that represent different engines, can be found in the original article on Chessbase.com, A Gross Miscarriage of Justice in Computer Chess (Part 2), aka The Rybka Affair. Was it a coincidence that the mid-2000s spurt in computer chess happened with the introduction of 64-bit processors?

In 'Modern Chess Engines', I picked up two factors related to advances in hardware. Again relying on chessprogramming.wikispaces.com for definitions:-

Bitboards • Also called bitsets or bitmaps, are among other things used to represent the board inside a chess program in a piece centric manner. Bitboards, are in essence, finite sets of up to 64 elements - all the squares of a chessboard, one bit per square. Other board games with greater board sizes may be use set-wise representations as well, but classical chess has the advantage that one 64-bit word or register covers the whole board.

Population Count (popcount, popcnt) • Determines the cardinality of a bitboard, also called Hamming weight or sideways sum. How many one bits exists in a 64-bit computer word? In computer chess, population count is used to evaluate the mobility of pieces from their attack sets. [...] Future or recent x86-64 processors provide a 64-bit popcount instruction.

The overhead of tracking and analyzing constantly shifting chess positions has been simplified and streamlined by these basic tools.

Mushroom Harvest

Like mushrooms after the rain, Fischer items pop up on eBay after any significant news on the 11th World Champion. The latest such news was the release of the movie 'Pawn Sacrifice'.

Here on Top eBay Chess Items by Price, the latest Fischer auctions were Fischer Insecure? (April 2014) and More Fischer - Spassky 1992 (January 2015). I could have chosen among several for today's post, but decided instead to go with a composite image. All but the lower middle item closed after the release of the movie.

A couple of the items pictured don't show the real final price. The item in the upper left, titled 'CHESS SET SIGNED BY BOBBY FISCHER AND BORIS SPASSKY' (from the 1992 match), sold for more than $3000. The item in the lower right, titled 'ICELAND CHESS Bobby Fischer vs. Spassky match 1972 - exceptional memorabilia', sold for $750. The upper middle item, titled 'Bobby Fischer JSA Certified Signed Autographed '66 Chess Book Pawn Sacrifice' was for the '1966 First Printing of Bobby Fischer Teaches Chess'.

If I had included items that were listed but not sold, the same composite image would show more than 30 auctions, including many unsold items relisted, often at inflated prices. Fischer would likely not have approved.

Chess Art Appreciation

Flickr places this watercolor at Hsinchu City. Wikipedia informs,

Hsinchu (also romanized as Xinzhu), officially known as Hsinchu City, is a city in northern Taiwan. Hsinchu is popularly nicknamed "The Windy City" for its windy climate. Hsinchu is administered as a provincial city within Taiwan. • Hsinchu

The painting is signed 'S.H. Chow 2015', which matches the name of the Flickr photographer.

Quick sketch © Flickr user Sheu Hau Chow under Creative Commons.

The full title is 'Quick sketch of people playing chess in the park today after breakfast'. Is it Western Chess or Chinese chess? To appreciate this painting, does it matter?

2015 World Cup Tiebreak

In the most recent post on my World Chess Championship Blog, 2015 World Cup Results, I noted an action:-

Add an explanation of the tiebreaks used. For the 2013 World Cup, I simply pointed to the page for the 2011 event. I plan to do the same for the 2015 event, but I should first confirm that the tiebreak systems were the same for all three events.

In fact, the same tiebreak system has been used for three consecutive World Cups: 2011, 2013, and 2015. The 'Regulations for the FIDE World Chess Cup 2015' restructured the tiebreak section, moving the more technical rules to an annex -- 'Annex 2 : World Championship Technical Regulations For Tie Breaks' -- but the rules were the same as in 2013.

The following table shows how many tiebreak games were played in each round ('Rd') of the 2015 Baku event. Columns headed '1' and '2' (plus '3' and '4' for Rd.7) count the number of games at standard time control ('90 minutes for the first 40 moves followed by 30 minutes for the rest of the game with an addition of 30 seconds per move from move one'). The other columns count tiebreak games.

After the standard games, the time controls for each subsequent pair of tiebreak games were:-

• 25 minutes for each player with an addition of 10 seconds after each move
• 10 minutes plus 10 seconds increment after each move
• 5 minutes plus 3 seconds increment after each move

These were followed, if necessary, by a so-called 'Armageddon' game:-

A single decisive sudden death game. The player who wins the drawing of lots may choose the color. The player with the white pieces shall receive 5 minutes, the opponent with the black pieces shall receive 4 minutes whereupon, after the 60th move, both players shall receive an increment of 3 seconds for each move from move 61. In case of a draw the player with the black pieces is declared the winner.

The table shows that Armageddon games were needed in the first three rounds.

'Good evening, Baku. This is Brussels calling!'

This post is a note to all those responsible for the organization and production of the just concluded 2015 World Cup in Baku. Great job! Well done! I can't possibly exaggerate how much I enjoyed watching the event.

As I mentioned in That's Not Bobby!, I missed the first three++ rounds and have been catching up with them in the official site's video archive. The 'Bobby!' post mentioned that 'I found the broadcast format somewhat clumsy', but it turns out that it was mainly an initial impression. What was I talking about? Here's a screen capture from the first day I started watching.

There are four blocks of information on the screen:-

• Two menu bars
• A game that I've selected to watch
• The broadcast (red 'WATCH LIVE' button)
• The chat room

That represents a ton of input for me and although it doesn't quite fit together on my screen, I can live with that. My main problem was that 25% of the screen was taken by those menu bars and I couldn't see how to remove them. Do I really need to be constantly reminded that the final round will start at such-and-such a time?

Since I don't want to end this post on a negative note, I'll add a big THANK YOU! to everyone responsible for showing how chess can be covered.

Chess Engines : LMR

Continuing with this series on Modern Chess Engines, in my previous post Chess Engines : Pruning, I omitted one topic because I didn't understand the explanation. Again relying on chessprogramming.wikispaces.com for definitions:-

Late Move Reductions (LMR) • Or its version known as History Pruning and History Reductions, save search by reducing moves that are ordered closer to the end of likely fail-low nodes. Typically, most schemes search the first few moves (say 3-4) at full depth, then if no move fails high, many of the remaining moves are reduced in search depth.

Fail-low, fail-high -- what's that all about? First, it's useful to insert a reminder that this pruning is being done on the tree of variations that flow from the current position. Here's a diagram.

From Wikipedia: Alpha–beta pruning

Chess engines are as much about constructing the tree efficiently as they are about evaluating the chess content of specific positions.

Fail-Low • A fail-low indicates that this position was not good enough for us. We will not reach this position, because we have some other means of reaching a position that is better. We will not make the move that allowed the opponent to put us in this position.

Fail-High • A fail-high indicates that the search found something that was "too good". What this means is that the opponent has some way, already found by the search, of avoiding this position, so you have to assume that they'll do this. If they can avoid this position, there is no longer any need to search successors, since this position won't happen

In other words, LMR means that if a move isn't looking particularly interesting, don't examine every subsequent response. Look at a few responses in depth, then look at the rest quickly. If nothing special is found, move on. Techniques like this are one reason that engines are able to calculate to amazing ply depths that seem to defy mathematical common sense.

Getting back to Stockfish, the engine that triggered this series of posts, there's a good discussion by Tord Romstad titled An Introduction to Late Move Reductions. The page disappeared while I was preparing this post ('This domain has expired'), but lives on in Archive.org.

Chess Curriculum - Susan Polgar

Continuing with this blog's Chess Curriculum Inventory, the S.Polgar Chess Curriculum (May 2015) is again at bat. Following a brief detour for J.Polgar's Chess Palace, it's time to give Susan full attention over her younger sister Judit.

Susan Polgar never does anything half-way and her chess curriculum is in keeping with the tradition. My May 2015 post showed that there are at least two versions available, but the differences are minor and I'll limit this post to the April 2014 version.

The curriculum consists of 30 lessons, with a page or two of material per lesson. The document lacks a TOC and although I created one easily, I'll mention only the first entry of the first few lessons.

Lesson 1 - Excite kids about the fun game of chess
Lesson 2 - Introduce the Pawn
Lesson 3 - How to use your Pawns more effectively
Lesson 4 - Introducing the Rook
Lesson 5 - How a Rook can best help (or fight against) a Pawn
[...]

The notes behind each lesson are light and the instructor will have to do some preparation, but this shouldn't be too onerous for an experienced chess player. The material looks appropriate for someone who knows how to play and is looking for a structured approach to teaching someone else. The inexperienced player will need more support.

At the end of the document is a summary of general points to keep in mind while playing.

Susan Polgar Power Principles of Chess
1. Control the Center!
2. Develop Your Pieces as Soon as Possible!
3. Castle as Soon as Possible!
4. Keep Your Pieces Protected!
5. Have Fun and Win with Grace, Lose with Dignity!

That last bullet -- 'Win with Grace, Lose with Dignity' -- is probably GM Polgar's personal motto and could be good advice for all competitive aspects of life.

Seeing Red Bull

From Youtube's CNNMoney channel: 'The only chess player sponsored by Red Bull. The company sponsors 600 athletes and pulls in record viewership. [...] The U.S. is making a chess comeback. Hikaru is one of three Americans among the top 15 players in the world and one of the fastest.'

Red Bull sponsors this guy to play chess (3:03) • 'Hikaru Nakamura is the only chess player in the world sponsored by Red Bull. CNNMoney's Vanessa Yurkevich plays the chess grandmaster and finds out why.'

For more about GM Nakamura, see Hikaru Nakamura - Chess on Redbull.com. Re 'The only chess player sponsored by Red Bull', what about Tania Sachdev India Chess Red Bull?

October 1965 'On the Cover'

Fifty years ago the 1965 Capablanca Memorial was featured on the cover of both major American chess magazines. The event has already been pictured in the September 1965 'On the Cover' for Chess Life.

Left: 'IVth Capablanca Memorial'
Right: 'Teletype Tourneyist'

Chess Life

Former World Champion Vassily Smyslov won the Capablanca Memorial tournament in Havana, finishing a half-point ahead of Borislav Ivkov, Ewfim Geller, and U.S. Champion Robert Fischer.

The six page CL article was mostly game scores and photos, plus two games lightly annotated by Fischer.

Chess Review

Robert J. Fischer shows a fierce intensity as he makes a move to be forwarded via teletype to his opponent in the Capablanca Memorial tournament in Havana. He played from the Marshall Chess Club in New York.

CR noted, 'A four or five hour game takes eight or nine hours over teletype', and quoted Fischer from an interview, 'It's a question of how soon I'll crack up'.