Schnapsen Log Archives
Columns for August, 2012
Make a Virtue of Necessity
August 2, 2012
The cake is gone, the coffee is refilled and steaming, and Peter still sits across from you at the Café Abeles, with Lore kibitzing. You couldn’t be more content. You and Peter have each shown a marriage and the trick point score is dead even….
Exit Cards, Stoppers, and Optimal Endplay
August 8, 2012
I am again going to break from our normal format, in order to tell you about a fascinating scholarly article that has a bearing on the Schnapsen endgame. The paper is very mathematical, developing a “calculus” of cards that allows you to look at the hand you were dealt, calculate the maximum number of tricks you can take, and determine a strategy for obtaining that maximum number of tricks. Sounds useful, doesn’t it? And, for the mathematically inclined, this calculus involves infinitesimals, which are “numbers” greater than 0 but less than any positive fraction such as 1/100 or 1/1000000000 that you can come up with. It’s all quite beautiful, in a way that only mathematics can be.
The paper is “Two-Person Symmetric Whist”, by Johan Wästlund, which was published in The Electronic Journal of Combinatorics in 2005. The author is a researcher in the Department of Mathematical Sciences at Chalmers University of Technology in Sweden….
A Theory Concerning the Last Trick
August 13, 2012
While we are on a break from our normal format, I’d like to tell you about another very elegant result by the mathematician Johan Wästlund, closely related to his results on the game of symmetric whist. Today’s topic is an optimal strategy for the sole purpose of winning the last trick. Since a reasonable fraction of Schnapsen outcomes are decided by who wins the last trick when the stock is exhausted, this question has a clear connection to Schnapsen strategy.
The paper of Wästlund that contains this result is “The Strange Algebra of Combinatorial Games”, written in 2009. This paper discusses several different sorts of games. The results we will discuss today are just from the paper’s Section 7.2, which deals with a version of the traditional Swedish card game Femkort (“Five-card”), in which the winner of the game is the player who wins the last trick.
The good news is that Wästlund’s results on Femkort are much simpler…
August 17, 2012
You are back at the Café Abeles, at your favorite table, playing cards with your buddy Peter. Outside it’s steaming hot and humid, but in here the ceiling fans and heavy stone walls keep things nice and cool. Cool enough that you’re enjoying your hot coffee while you play.
It’s been a close game so far and you’re in the endgame of a close deal where no one declared a marriage and the stock has just been exhausted….
August 20, 2012
It seems as though your coffee hasn’t even had time to cool at the Café Abeles when you find yourself once again in a quandary….
Order from Chaos
August 24, 2012
Lore has once again taken Peter’s place across the table from you at the Café Abeles. As friendly as Lore is, she’s a much more intimidating opponent than Peter is. You’ve noticed some surprising plays from her, and you suspect that there have been many more that were too subtle for you to notice….