Thursday Jun 26, 2008

Where Not to Run

Reuti just reminded me of a nice application of one of the new features we added in Grid Engine 6.1. Before 6.1, resource requests were limited to simple boolean AND and OR expressions. For example, when submitting a job, a user might request "-l a=sol-x\*|sol-amd64 -l mem_free=4G -l exclusive=TRUE", meaning that the job must run on a Solaris i386 or AMD64 machine, and the machine must have at least 4GB of memory free, and the job wants exclusive access to the host. (AND is represented by multiple -l switches.) There was no way, however, to request, for example, Solaris on anything but x86.

Enter 6.1. With 6.1 we introduced full boolean expressions for resource requests. A user can now make requests like, "-l a =sol-\*&!sol-sparc\*". (The job must run on Solaris, but not on SPARC or SPARC64.) Even better, you make create complex boolean statements, like "-l (sol-\*&!\*-x86)|(lx2[46]-\*&!(\*-x86|\*-ia64))". (The job must run on either Solaris on anything but x86 or Linux on anything except x64 or Itanium.)

Now, to the title problem. In the email that prompted this post, Reuti responded to a question about how to submit a job to any host, except for one. With 6.1, the answer is simple. Grid Engine has a built-in complex called hostname, or h for short. Using the new boolean expressions, it's very simple to request "-l h=!badhostname", which allows the job to run on any machine except the one named badhostname.

Monday Jun 23, 2008

Announcing Grid Engine 6.2 Beta 2 Binaries

I'm a little slow on the draw, but in case you haven't noticed already, Grid Engine 6.2 Beta 2 is now ready for download! Go pull it down and give it a whirl!

You should also have a look at my slide deck from SuperComputing '07 talking about what's new in 6.2 You can find it on the OpenSolaris HPC Community's presentations page.

Monday Mar 05, 2007

Bishops Versus Knights

Here's an interesting video from a GM explaining some of the strategy involved in owning a knight pair or a bishop pair in the end game. Worth the 10 minutes to watch it.

Saturday Dec 23, 2006

The Mystery of Blindfold Chess

Here's an interesting article from the Starbroek News, an online news site that appears to be based in Guyana, of all places.

Tuesday Oct 17, 2006

Amazing Smith Morra Grace

What once was lost... I previously wrote about a great article on beating the Sicilian with the Smith-Morra gambit, but unfortunately, shortly after I posted the entry, the article disappeared. I just managed to find it again. To prevent losing it a second time, I have archived a local copy.

Tuesday Jul 25, 2006

Nifty Little Tool

I just happened across this PGN viewer. Not the most amazing applet I've ever seen, but handy nonetheless.

Sunday Jan 29, 2006

ChessGames Companion

A while back, I blogged about the Opening Explorer on ChessGames.com. It's a great tool that lets you walk through a chess game and see, at every step, the next possible responses ordered by popularity, and a list of games that start out the same way. It's nice because it lets you see if the next move your planning is crazy or plan for what your opponent is mostly likely to do next. I've always found, though, that it lacks context. I usually end up playing through some of the listed games to get a feel for why the moves are happening.

This morning I found another great tool that fills in the gaps. It's ChessOps - A Basic Guide to Chess Openings. ChessOps allows you to walk through the classic openings and gives a running commentary on why each move was made. It also gives you pointers about transition points, such as transitioning the (Smith-)Morra Gambit into the Alapin variation. ChessOps is more limited than ChessGames.com because it restricts you to the classic games. If you try to make a move that doesn't fit the established pattern, it tells you that you can do better and tells you to try again. However, for those of us still studying openings, this site is perfect. I wish I had found it six months ago.

On a side note, last night Firefox pointed out something interesting. GameKnot, my favorite online chess site, offers your current game list through an RSS feed! I now have a live link on my toolbar that tells me whenever it's my turn to make a move in one of my games.

Thursday Jan 26, 2006

Fast Chess

A couple of days ago I accidentally got into a "fast" game with a guy on GameKnot. He wanted to play without spending more than a few seconds thinking about moves. That, of course, also meant that he wanted to play in real time, not a move every couple of days.

I have been spending a lot of effort lately in learning and understanding the intricacies of the Ruy Lopez and the Sicillian Defense. It's made my chess games painful because in the beginning, when the game should be flowing smoothly, I'm spending a ton of time doing research. Boy did it pay off in this fast game, though! It was immediately obvious that I was following a rote script, and my opponent was making it up as he went. The result was that, even though I was playing black, I held the initiative through the entire game. I was able to maintain good form and a solid defense while making my opponent scramble to keep up.

My point here is not to brag. (I'm only playing at about a 1400 level, so there's nothing to brag about yet.) My point is how envigorating it was to have all that time spent feeling dumb because I was researching basic openings, translate into beautiful technique in a real-time game. I felt like Daniel-san in Karate Kid when Miyagi finally demonstrated the point of all the chores. It's just nice to know that I'm not too old to learn new tricks.

Monday Aug 29, 2005

New Board

One of my hobbies is collecting chess boards. Every time we go somewhere interesting, I try to buy a board with some local flare. We were in Istanbul this weekend, and I bought a beautiful board there. It's decorated with inlaid wood and mother-of-pearl, and has a backgammon board on the inside. Because the chess pieces at the shop weren't interesting, I only bought the board, but it did come with backgammon chits and some dice. It's about 18" (~46cm) square and was very reasonably priced, all things considered. Here are some pictures:

Chess Around the World

Since being in Europe, I've noticed that we don't all call our chess pieces the same things. I find the differences fascinating. Below is a table of the names of the pieces translated into English. So far, I only know about German and Bulgarian names. If anyone from any other countries/cultures would like to contribute, please add a comment.

American KingQueenRookBishopKnightPawn
German KingLady\*TowerRunnerJumperFarmer
Bulgarian KingQueenCannonOfficerHorseFoot Soldier
Turkish\*\* KingVizierCastleElephantHorsePawn
Spanish\*\* KingQueen/LadyTowerAlfil\*\*\*HorsePeon
French\*\*\*\* KingLadyTowerJesterKnightPawn

\* I suspect that the Germans use "lady" instead of "queen" because in German, "king" (König) and "queen" (Königin) both start with 'k'. "Lady" (Dame) doesn't, which makes game notation easier. The same thing applies to playing cards.

\*\* Thanks, Ahmet!

\*\*\* The spanish word, el alfil, does not appear to have a meaning outside of chess. As Ahmet suggested in his comment, it seems likely it's derived from the Arabic word for "elephant."

\*\*\*\* Thanks, Bruno!

(I just happened across this site, where there's a much more thorough list of chess piece names, but they don't translate them back into English!)

Monday Aug 08, 2005

Dirty Chess

Until recently, my approach to chess has been to rely on my opponent's weaknesses instead of my own strengths. I never had a plan, really. I would just wait for my opponent to make a mistake and then beat him or her over the head with it. If my opponent never made a mistake, then I would lose. That led pretty naturally to the habit of playing chess "over a few beers." Intoxicated people make more mistakes than sober ones.

(A curious side effect of relying on my opponent to screw up his or her strategy, instead of having one of my own, is that if my opponent had no strategy, I would also lose. Until recently, someone who had never played chess before had about a 95% chance of beating me. Without a plan of my own, aimless, random moves left me nothing with which to work.)

Now that I'm taking chess a little more seriously, I have stopped relying so heavily on my opponent's mistakes. Mostly. I just finished a game, which I won by giving my opponent several yards of rope and waiting for her to hang herself. It worked, but it left me feeling dirty. I didn't win the game because of my brilliant moves, but rather because of my opponent's oversight. What's worse is that I did it on purpose. I feel like I just stole money from a child.

Sunday Jul 17, 2005

The Four Pawns Attack Against the King's Indian Defense

Here's another paper on chess tactics. This one is only moderately useful. I read this paper because I am in a game where my opponent used the Four Pawns Attack against my standard queen line defense, the King's Indian. By doing some research and being careful, I have managed to keep the playing field approximately level. However, the fact that it took so much effort to maintain even footing with the King's Indian Defense speaks volumes about the Four Pawns Attack. (Either that or my opponent is that much better than I am. He doesn't have a rating yet, so it's hard to be sure, but I'm guessing he's in the neighborhood of 1400-1500.)

Saturday Jul 09, 2005

Rock My Chess World

This site is fragging amazing! Yes, I'm a chess nerd, and perhaps I'm easily impressed, but that doesn't make chessgames.com any less noteworthy. First of all, they have an online, searchable database of about a third of a million games, dating back to the 1800's. Second, the database is searchable by ECO code (among other things). If you know, for example, you're playing the Four Pawn Attack against the King's Indian Defense, you can find its ECO code, E76, and then search for all the other games that opened the same way. Nifty

The part that is irrationally cool is the Chess Opening Explorer. Once you've looked up an ECO code on the main site, you can launch the Chess Opening Explorer for that opening. You then click through the follow-up moves, with each step showing you win/draw/loss statistics from their database for that continuation. Go try it!

Perhaps this technology is nothing new. It sounds like Fritz may do something similar, but just getting started playing research-augmented chess, this site blew me away.

Tuesday Jul 05, 2005

The Smith-Morra Gambit System Against the Sicillian Defence

I love nerds. (I am a nerd.) Chess nerds are the best, though. There's some kind of uniting drive to find the optimal series of moves in response to any other given series of moves. The net result is that some day, the entire game will be determined by each player's first opening move. The rest of the game will be predetermined by some book, of which everyone will have a copy.

Seriously, though, I've just started taking chess seriously, and the copious amount of documentation about every possible combination of moves is very helpful. As an example, a friend of mine and I just got into a game, and he decided he wanted to play the Sicillian Center Game. (He was playing white.) So, I looked up the Sicillian Center Game on About Chess and followed his lead. Of course, the Sicillian Center Game is not advantageous for white, so he fell back into the Smith-Morra Gambit (which is on the same page at About Chess). There wasn't enough useful information there, though, so I searched Yahoo! and turned up this paper. It's an excellent treatise on the strengths of the Smith-Morra Gambit. By reading between the lines, one also gets a clear picture of the weaknesses.

So, using this paper as a guide, I played the trap line, and while my friend didn't fall for it, it did leave him off balance enough to cancel out the advantages gained from the Smith-Morra Gambit.

I suppose by rattling on about this topic, I'm proving that I too am a chess nerd. I just hope someday I learn to play like one! (Come challenge me at GameKnot! My username there is templedf.)

Monday Jun 13, 2005

Starting From Square One

Since I've started playing chess on GameKnot (My username is templedf there. Come play me!) I've become painfully aware of what a disadvantage never having studied chess really is. While my opponents very often whip off the first four or five moves from rote memory, I start struggling with the first move. Same goes for end games.

To correct this problem, I've started doing two things. First, every time I play someone, I look their opening up on the web. I can then read about it, learn how best to play against it, and potentially use it myself in the future. A friend showed me a neat trick for finding openings on the web. Go to Google, and enter the opening's notation as the search text. For example, if you search for "1. e4 e5 2. Nf3 d5," you will discover this opening is called the elephant gambit, and that it's not used very often because it doesn't ofter enough in return for the pawn.

The second thing I started doing is reading chess advice on the Internet. There are a large number of chess sites out there, many of which have useful advice sections. About.com's chess site has a neat feature where you can play through an opening, and it will tell you what it is. Unfortunately, though, their library is pretty narrowly focused on the mainstream moves.

The best site I've found so far, though, is Chess Kids. Yep. I'm learning chess from a site designed to teach 8-year-olds. There are 9 classes, with each class divided into 6-8 lessons. The first lesson is what the pieces are called and how they each move. Not exactly useful for someone who's been playing chess for 20 years. Fortunately, though, the lessons ramp up quickly. I'm currently in class 8 learning about the Sicilian Defense and the French Defense. In class 7, I learned about how to win or draw an end game with just kings and pawns. If you can get past being talked to like you're 8, this site provides a really good primer/refresher in the study of chess.

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