Chess puzzle #21 (medium)

August 23rd, 2008

I (black) blundered here by taking that pawn on f3:

White to move and win material

White to move and win material

Hint 1: show

Hint 2: show

Fortunately my opponent (white) didn’t see the solution and tried Rf1:

Black to move and retain some of the material advantage

Black to move and retain some of the material advantage

Hint 1: show

Hint 2: show

Solution: show

Chess puzzle #21 (easy)

August 21st, 2008

Blunder by white (me)! I just took a black pawn with my rook.

black to move and win material

black to move and win material

Black to move and win material.

Chess puzzle: The missed chances (medium)

August 7th, 2008

Today both me and my opponent missed a chance to turn the game around.

1. Find a better move 15 for white which wins material.

2. Find a better move 29 for black that wins material.

Chess puzzle: Who is the one in trouble? (tough)

August 5th, 2008

Once again I (black) got in trouble after my opponent engaged multiple threads at once with 20. f4:

Who is the one in trouble?

Who is the one in trouble?

I used up almost all my time to think of a way out. Usually there is one in such a situation. But I didn’t see that actually there was not only a way to get out with minor material disadvantage, but even with a significant advantage!

Black to move and win material.

Hint: show

Solution: show

My own “solution” was a bit puny. If you look at how I won, please consider that after that situation I had only two minutes left :-)

Chess puzzle: Win faster (easy)

August 4th, 2008

Once again my newly gained endgame powers saved a game in which I messed up the middle game. Thank you, Josh Waitzkin! Great tutorial. I played the whole endgame through the 10 second Fisher time, since I was already down to 4 minutes at move 35.

At the latest after my move 52 it is obvious that I am winning. But there is a better way. After 52. ...Bxc7, how could I (white) have gained a queen faster?

Chess puzzle #16 (easy)

August 2nd, 2008

I (white) set up a trap here.

White threatens trap

White threatens trap

Question 1. What’s the threat against black? show
Question 2. Black to move. Get out with even material. show

uCertify review

July 25th, 2008

Recently the PR department of uCertify approached me and asked me to blog a review about their exam preparation kit. Since this is an interesting topic to me (see my posts Whizlabs vs. Enthuware, and Effective Enthuware) and since I would get a free simulator, I agreed.

uCertify produces preparation kits for many different IT certifications, including SCJA, SCJP, SCJD, SCWCD, SCBCD, SCMAD and SCDJWS. I got the one for SCBCD 5.0 (Sun Certified Business Component Developer for the Java Platform, Enterprise Edition 5, CX-310-091), which costs USD 59.99, to test it. I used the uCertify PrepEngine Version No: 12.21.05.


  • A nice looking user interface with good usability, especially regarding all the little things. For example it is possible to click on the answer itself, not only on the checkbox next to it. Several keyboard shortcuts are available.
  • It has an optional study mode for every kind of test. When enabled, it says immediately which answers were wrong, rather than evaluate all answers only after they have been given. This provides a more harmonic way of learning and measuring progress.
  • It automatically shuffles the order of the answers. That’s an awesome feature that I miss in Enthuware and Whizlabs! It prevents me from remembering the position of the right answer instead of really learning the right answer.
  • The explanations to answers are good and include diagrams where it makes sense.
  • Huge amounts of study material are included! It is not only a simulator, it is a full preparation kit, just as promised.
  • Aside from the option to study the topics using small articles in the style “What is the PreDestroy method?” and larger articles about complex topics, there is an interactive mentor that almost provides the feeling of having a real private teacher. In small chunks it presents the exam topic as specified by Sun, then explains it, and afterwards asks me a question about it to check whether I understood it.
  • There is a feature to discuss any single question with others, similar to a forum thread. Once there are more users this can be very useful. I tried it a few times, and it took more than a day to get my comments “approved”. Hope that gets better.
  • Questions can be assigned a custom tag. For example I can give several questions the tag “unsure” or “do again before exam” and then create a custom test based on the tag. I would highly recommend to use this feature to assign box IDs according to the Leitner System, similar to how I described it for Enthuware in Effective Enthuware. (Note that numbers and short names are problematic, so use for example “bbbb” for box 2.)

    uCertify custom test screen

  • There are lots of features which I didn’t cover in this review, because there are so many. I covered the ones I considered important to my way of learning, but one of the other ones might just be the feature you always wanted.
  • Question quality and exam topic coverage: I trained for a section using Enthuware until I was able to answer all questions in Enthuware corectly. After that I tried questions for the same topic in the uCertify simulator. I passed on the first try, but there were some exam-relevant topics that had not been covered enough in Enthuware! (Concrete example: It is possible to get through the Enthuware questions without fully understanding MEMBER [OF] in JPQL. uCertify did not let me get away with that.) Nothing against Enthuware – it is possible that this test would have worked the other way round in the same way. Simulators have different strengths and weaknesses.


  • It doesn’t have a direct way of selecting a range of questions. For example I can’t easily create a test with questions 1 – 6 of topic X and later questions 7 – 12 of topic X. (To do that, I have to add all questions to the pool, sort by ID, then delete some of them, remember which ones I deleted, do the others later.)
  • Support. I used the general support, not the one for paying customers, because I am not really a paying customer. My questions were answered only partially sometimes, and one of three support requests was ignored completely. Let’s just hope they provide better support for normal customers.
  • The license is complicated. I asked the support about it, but still don’t understand if I can install the product years later on different hardware. An on-line activation is required. I wouldn’t recommend buying it if you are planning to use it for longer than a year, unless you sort this out.
  • Getting the custom tags, an important feature (see above), to work was a challenge. First I tried tags like “1”, or “2”, and they just didn’t show up in the custom test dialogue. Then I tried “a” and “b”, still no success. So I tried “11111” (maybe it’s a length issue?). Then it showed up, but when I tried to add the questions with that tag, only two or three, it added more than 100 to the question pool. In brief, my impression is that there are certain rules for tags: 1. At least 3 or 4 chars; 2. no numbers (or not only numbers?).
  • Portability – requires Windows. Maybe one of the thin emulators like Wine can handle it? VMware certainly can.
  • The integrated help is a single, huge page.


uCertify provides more than Enthuware or Whizlabs. I cannot answer the very important question of which simulator provides the most relevant questions regarding the real exam, and if someone who uses the complete preparation kit of uCertify will get a better result in the real exam than a low budget learner with Enthuware plus free study material. More fun with uCertify – well, that’s indeed possible due to the nice user interface and the interactive mentor. The complicated license and poor support are a problem.

Learning chess with the computer

July 20th, 2008


I am not a very good chess player, although I have played for 25 years. My FICS rating is below 1800. So you may first consider a chess learning guide by someone more experienced. This guide might still help when you want the opinion of someone in the same class.

One thing I have been planning for over 10 years is to improve my chess skills by a whole level. This year I did, and I was stunned by the great new ways that computers and the internet offer for beginners and intermediate players to learn, compared to what I had in the 80s.

Interactive Tutorials

I found it far more effective to use an interactive tutorial than to read a book. A good interactive tutorial asks questions, like tiny exercises, which force the reader to do something on the board. The additional gain compared to reading a traditional chess book is huge. The solutions that are out there do not fulfil all my dreams, but they are quite nice.
Chessmaster explains about forks

  • Chessmaster Grandmaster Edition has many tutorials. The most helpful one for me was the one by Josh Waitzkin. It taught me not only the direct chess strategies I needed to get to the next level, but also to express myself with chess as a form of art and to develop my character and my personality along with my chess skills. Chessmaster Grandmaster Edition is very affordable, but hard to get in some countries.
    One of Chessmaster\'s interactive tutorials
  • The interactive mentor at is also available as stand alone software at Either are very expensive (the web version is a subscription with a monthly fee). Another weakness is that it doesn’t have many features compared to Chessmaster. It is a very primitive software. For example most moves are not shown on the board and are just there to read in PGN, so I end up having a hard time following it, similar to reading a book. But the lessons have a high degree of interactivity and are of a very high quality. Especially regarding positional play and middle game strategy it covers many things that Chessmaster doesn’t cover well, and it does so at a very high level. Most lessons have been created by the renowned IM Jeremy Silman. All lessons require to be solved on the board by making a particular series of moves. When the user makes a “wrong” move it sometimes is explained very well why it is wrong or that it is fine, too, but in some cases it isn’t. But it is impressive how many possible answers are covered and properly commented. Anyway, that’s basically all it does. That’s about 3 % of the features Chessmaster has to offer. But really, great quality, very valuable information.

Post-game computer analysis

This is such an incredible help! After I played a game (against a computer or against a human) I always feed it to a computer and get an incredibly useful analysis. It comments on my moves, finds all tactical blunders and so on. You can’t imagine how much this has helped me to get better! While it doesn’t miss any tactical opportunity, it is no help for strategy at all. That would require a human mentor to look at my games. The next best thing are probably the positional and strategy lessons of Chess Mentor (see above). They present a position in the late opening or middle game and then require to find a good strategy to be provided by a sequence of moves.

  • Chessmaster Grandmaster Edition can analyse any game in PGN format with short algebraic notation.

    Pro: It has audio output and comments on more aspects than any other analysis software I tried. For example when I do a particular unusual opening move it says something like: “Ah, interesting. That’s the Steinitz Attack. Some guy named … has used it around 18.. with great success. It became less popular when …d6 has been discovered. After that move white has no advantage left from this move. (…)” Such facts become very interesting when they refer to a game I just played, as boring as they would otherwise be! Another advantage is that it directly says why my move is not good.

    Contra: It is inconvenient to browse the move alternatives slowly and manually and to try additional variations.
    Chessmaster analyses a game

  • Common chess engines like Crafty can be plugged into a fool-proof frontend like BabasChess.

    Pro: Great navigation options to browse the suggested alternatives, very easy to let the computer answer “but…” and “what if” and “but what if …” questions regarding its own suggestions or anything at all, actually. Chessmaster Grandmaster Edition might leave you alone with troubling thoughts like “I don’t have a good feeling about the alternative it suggested. It only works because black plays along in move x.” while the combination of a chess engine and such a frontend will easily show any subvariation you can think of. It’s like a neural interface.

    Contra: The output follows a primitive scheme, while in Chessmaster Grandmaster Edition you have the feeling of being mentored by an AI from the future. No comments on opening moves at all, and no explanations like “this is a better move because it pins the black knight to the black queen”, which Chessmaster can provide.

Game explorers

When studying openings I found it very disturbing that often the main line could easily be disrupted by a move that looks far greater. The books don’t say anything about such variations. There are many, many moves in the openings and early middle games that look great, and it is very hard to find out why they are not great and what to do if someone plays them. Game explorers help to see what grandmasters played against an unusual, but not entirely far-fetched move. They are great to learn a particular class of opening moves or repeating early middle game lines. When I read a book back in the 80s it always left me alone with thoughts like “But that will never work when black does …” and then when I tried it black does exactly that, and I was still helpless and would better not even have started to read about it.

  • has a good one, but it is not free
  • Red Hot Pawn has a free one, but there are not enough professional games in the data base to make it really useful

Chess puzzle #15 (medium)

July 19th, 2008

I didn’t see the opportunity. Do you? Black to move and win material.
Chess puzzle #15

Glassfish: WebService in Session EJB

July 13th, 2008

I just got the strangest error message when trying to use a stateless session EJB as a WebService in Glassfish v2 u1:

[#|2008-07-13T16:41:25.366+0200|SEVERE|sun-appserver-pe9.0||_ThreadID=12;_ThreadName=Thread-31;_RequestID=d816d64c-543d-47ac-b339-2231f346754e;|Exception occured in J2EEC Phase
	at com.sun.enterprise.webservice.WsUtil.runWsGen(
	at com.sun.enterprise.webservice.WsUtil.genWSInfo(
	at com.sun.enterprise.deployment.backend.AppDeployerBase.loadDescriptors(
	at com.sun.enterprise.deployment.backend.AppDeployer.deploy(
	at com.sun.enterprise.deployment.backend.AppDeployer.doRequestFinish(
	at com.sun.enterprise.deployment.phasing.J2EECPhase.runPhase(
	at com.sun.enterprise.deployment.phasing.DeploymentPhase.executePhase(
	at com.sun.enterprise.deployment.phasing.PEDeploymentService.executePhases(
	at com.sun.enterprise.deployment.phasing.PEDeploymentService.deploy(
	at com.sun.enterprise.deployment.phasing.PEDeploymentService.deploy(

Apparently there is a problem in this Glassfish version that prevents it from showing the proper Exception as JAX-WS reports it. The verifier only barfed random shit at me, too.

I updated to the lastest Glassfish to get a better error message, but then it even worked without an error. Strange days.