Psellos
Life So Short, the Craft So Long to Learn

The Schnapsen Log

July 22, 2012

Avoid the Ducking Ruff (close stock)

Martin Tompa

Uncle Hans once again restores the cards on the table to the position at the beginning of trick 5, when Claudius was on lead.

“Closing the stock is particularly appealing, as Claudius could win 3 game points, since you’d taken no tricks yet,” Hans goes on. “Claudius would need to set up his T as a winner in order to collect enough trick points. That means starting out by leading Q. It’s ironic, since this was his actual lead that brought us to the ducking ruff with the stock open. With the stock closed, the worst that could happen to him would be if you won with A, cashed A, and led another heart to force him to trump, a forcing defense. Here’s what it would look like after he trumped your heart.”

Unseen cards:
KJ
K
♣ —

Claudius: (44 points)
A

♣ —
T

“His only hope at this point would be that one of those trumps was in the stock. He’d have to cash A and hope that his final T isn’t trumped. In that case, he would have 71 or 73 points, depending on which trump was in the stock. If either Q or K was in the stock, he’d only get to 57 or 58 points and would lose 3 game points. If either red ace was in the stock, he’d have an easy time winning, since he could force you with a diamond lead before you could force him with a heart. The more interesting of these two cases is when A is in the stock. Here’s what it would look like after you won A.” Hans rearranges the cards on the table.

You: (14 points)
KJ
KQ
♣ —

Claudius: (38 points)
AQ
T
♣ —
T

“The best you could do would be to lead Q. Claudius would win with T and do his own forcing defense by leading T. He would then take his last two trumps for 71 points in total.”

Hans concludes, “All right, then, it’s time to analyze Claudius’s expected game points. He wins 3 game points as long as neither K nor Q is in the stock, and loses 3 game points otherwise. That means his expected gain is ⅔(+3) + ⅓(−3) = 1 game point. So how does this compare to him leading T with the stock left open?”

“It’s exactly the same!” you reply.

“Yes, dear,” Hans says. “On average, repeating this play many times, it’s exactly the same. The difference is in the outcome when you play it only once. At the beginning of the deal, the game points score was 4 for Claudius and 6 for you. If Claudius leaves the stock open and leads T, the score at the end of the deal is guaranteed to be 3:6. If Claudius closes the stock, the score will be 1:6 two-thirds of the time and 4:3 one-third of the time. This is the only reason to choose one over the other. Remember to keep your eye on the game point score when you’re planning your plays.”

© 2012 Martin Tompa. All rights reserved.


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About the Author

Martin Tompa

Martin Tompa (tompa@psellos.com)

I am a Professor of Computer Science & Engineering at the University of Washington, where I teach discrete mathematics, probability and statistics, design and analysis of algorithms, and other related courses. I have always loved playing games. Games are great tools for learning to think logically and are a wonderful component of happy family or social life.

Read about Winning Schnapsen, the very first and definitive book on the winning strategy for this fascinating game.

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