Is there any reason it blocked itself?

[AyunuS]

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I just finished a free automated fun tourney, where I had a robot make a play I thought was really sad. If it just didn't block itself on spades, it could have easily had 2 more tricks, and I see absolutely no advantage to it blocking itself, but there was an obvious disadvantage in that it couldn't use the last 2 spades from my hand. Is there some hidden advantage to this or did it just do something stupid?

[Stephen Tu]

There's no disadvantage or advantage; from GIB's point of view the cards are equal, because if it doesn't block itself, North can simply hold-up. You only get one spade trick regardless. Granted, not blocking the suit is better against truly horrible North players who can't figure out hold-up play despite partner showing out and dummy having no entries. But GIB analyzes from the point of view of perfect double-dummy defenders on the sample possible hands.

[dicklont]

There's no disadvantage or advantage; from GIB's point of view the cards are equal, because if it doesn't block itself, North can simply hold-up. You only get one spade trick regardless. Granted, not blocking the suit is better against truly horrible North players who can't figure out hold-up play despite partner showing out and dummy having no entries. But GIB analyzes from the point of view of perfect double-dummy defenders on the sample possible hands.

On this hand it made no difference.

But GIB will sometimes find North with AK in which case the lucky extra tricks are gone.

 

What was that 2D call by the way?

North has the perfect hand for a take out double.

But that's a human being so probably even more unpredictable than GIB.

[AyunuS]

Oh sorry I didn't really think about that. I was just assuming north was going to take the second round of spades regardless since I don't assume perfect defense, and its often very far from it in these tourneys.