FORTH GO

My opponent for the fourth round had beat me twice in last year’s G15 tournament, but the games were close enough that I had hope of getting 1 out of 2 points and making a respectable showing in the A bracket.

I was White in the first game opening up with a Queen’s Gambit Declined with some early pawn action on the queenside to reach the first shown position. It looked like I could take the pawn at a5 with my rook, but I soon realized he was setting a trap for me.

If I took the pawn, he would take my bishop reveaing an attack on the rook. I calmly castled instead, and he traded bishops anyway.

I then started to put pressure on the a pawn. He decided to let me have it instead of getting all bottled up trying to defend it. Black can add a second defender to the pawn with Qd8, but I’m not sure he can add a third before I can add my queen as a third attacker. The pawn didn’t seem that valuable anyway since my extra pawn was doubled.

After taking the pawn, we had a rook stand-off, and I took the opportunity to trade them all away since I often run into time trouble. After symmetrical knight invasions and threats, we reached the next position. Black could have traded knights while winning a pawn and leaving both sides with fractured pawn formations, but he had his sights on my king, thinking he might get a killer knight fork on f2.

However, the attack did not pan out, and after getting my knight back on the kingside to counter any further threats, I offered to trade queens before seeing a better use for my queen. Black refused to trade, and I had to offer again to get my queen back into position for the attack (this time I didn’t want him to take the trade). After he declined the trade again, we arrived at the next shown position. Now it was time for the attack.

With his forces away, I was able to invade his king’s position starting with Qg6+. Taking two pawns gave me a strong position in the final diagram, but how to finish? With less than two minutes remaining on my clock, I was fortunate to see a combination to trade queens and win a pawn and knight to boot. After Qxc7+ Kxd7, Nxd5+ produced the fork to win back his queen. From there it was simple to promote pawns and win.

As I was documenting something as innoculous today, I thought I better double-check my spelling. Google works well as a spell-checker, either giving you a definition link or suggesting the correct spelling if it’s not a word. For once, Google was at a loss for words. It offered neither definition nor correction but just links to 590 pages using the word. 590 links is a pretty good sign a word is misspelled, and badly misspelled at that; by comparison, incredable gets over 150,000 hits (and a suggestion with the correct spelling).

Next I tried the dictionary widget that comes with OS X 10.4. No luck there after trying several possible alternatives. Unlike a real dictionary, I was unable to browse for words that started with, say, inno which would help me out in case of any unsuspected silent letters. Noticing the widget also had a thesaurus (32,000 Google hits for thesauras), I looked up synonyms for harmless and immediately found innocuous. Of course!

Later I tried my email app’s spell-checker on innoculous and it did figure out what I meant.

During my brief tenure as editor of the XML Schema 1.1 Primer, I added a general description of schema processing and a couple of explanatory diagrams. Though I made them in the vector-based drawing program, OmniGraffle, I could only provide bitmap versions since the program’s vector format was proprietary. The latest version, however, adds an SVG export feature, and I’ve finally gotten around to posting the diagrams to the Schema comments list, in case the Working Group has any interest in using them.

The first diagram shows the common view of schema processing: one xml instance document validated against a schema to produce a true/false result, valid or invalid.

The second diagram shows the schema processing model more fully, where the schema is really a composition of zero or more schema documents and schema information from other sources, such as a repository, and the result is a “Post-Schema-Validation-Infoset” (PSVI). This PSVI is just an augmented version of the original XML instance document (its Infoset actually) so that most every tag now has metadata indicating its type and validity, among other things. Taking the whole PSVI into consideration, a true/false flag is not really enough to describe the outcome of validation—it is possible for a document to be partially valid, even.

I haven’t been following the XML Schema WG lately, and I’m not even sure if the next version of the specification will have a Primer.

I’ve added some new solving techniques, a small puzzle database, and a rating system (not shown). I’ve also been doing some research, and discovered several other techniques I need to implement, though they are too esoteric to show up in the puzzles you would find in a newspaper. There is only one truly new technique since my last update: Owning Segment. The other new techniques are special-cases of existing ones. Owning Segment finds a 3-cell segment that must own a particular value and then removes that value from competing cells.

I cleaned up the solving code by making the solvers sort of pluggable, though I broke the step-and-highlight mode. I’d like to work on the display if I can get Swing to do what I want (component sizing seems to be tricky).

The Jane Comfort Dance Company performed two wonderful pieces at Memorial Hall last week-end. To me, most modern dance is little more that athletic exhibition mixed with grace, but these dances told stories that even I could follow.

I lost both of my round 3 games against another top player. In the first game, as White, I made the mistake of going after a pawn while leaving myself open for an invasion by Black’s queen. In the first diagrammed position I have the e4 pawn attacked twice while it’s defended once, but making the capture leaves my king exposed for an attack. I should have made a developing move instead, such as getting my bishop out to allow castling. (”First to castle, never hassled” was what the great Polinski used to chant.)

The second position shows the quick penalty for my mistake. Not only is he going to get the pawn back, but I will lose more material, too. Luckily, Black didn’t find the very best moves, and I was able to parry the attack being down only a knight for a pawn. But further mistakes by me allowed him to quickly convert the advantage into a win.


I played Black in the second game, and my position looked pretty crummy coming out of the opening with two sets of doubled pawns, but I did have some hope for improvement. The extra f pawn could be used for attacking, I might coerce an exchange at c6 to undouble that pawn, and the rook might be able to attack on the half-open h file. The first two of those ideas came to pass, and I ended up with a favorable position after a few exchanges, as seen in the second diagram of this game, plus I had the “advantage” of two bishops vs. two knights.

Unfortunately, this is where I blundered, not noticing that the e7 pawn was attacked twice. Once he broke up the pawn chain, I couldn’t keep the remaining pawns all defended and soon lost.

The Handspring Puppet Company was in town for two Memorial Hall performances of Tall Horse plus a few sessions with UNC art classes. The life-sized puppets were certainly impressive, and the telling of the 19th century story of Eqypt’s gift of a giraffe to France has a lot of potential, but the final tally was disappointing as it was difficult to follow the dialogue with some actors using thickly accented English and others using French (with supertitles, if you happened to notice them above the stage). We could get enough to follow the story loosely, but could only get a glimpse of the political humor that was sprinkled thoughout the story.

The framework of the play was very interesting. Even while the audience was filing in, the players were already in character on stage miming tasks in a museum warehouse, such as filing and examining artifacts. The play begins in earnest with a French scientist coming to investigate a new find. When the staff finds the scientist lacking any historical context, they offer to educate him with a puppet play telling the story of the early interaction between Eqypt and France. This play within a play was a clever way to ameliorate the disruption of seeing the puppeteers standing behind the puppets.