Defensive error, or defensive doublecross?

[Siegmund]

More an interesting bridge hand than a bug report.

 

The bots have a nasty habit of always finding the killing shift in situations where human players make obvious-but-wrong returns of partner's suit, etc.

 

Tonight I knew what I was afraid of, and got fooled when a bot didn't see how to set me:

 

http://www.bridgebase.com/tools/handviewer.html?lin=pn|Siegmund,~~M29663,~~M29661,~~M29662|st||md|1S36QH8JAD56KC5JKA%2CS2JAH479D3TAC678T%2CS578TH5QKD248QC9Q%2C|rh||ah|Board%203|sv|e|mb|1C|an|Minor%20suit%20opening%20--%203%2B%20C%3B%2011-21%20HCP%3B%201|mb|p|mb|1S|an|One%20over%20one%20--%204%2B%20S%3B%206%2B%20total%20points%20|mb|p|mb|2N|an|Jump%20in%20notrump%20--%203-5%20C%3B%202-5%20D%3B%202-4%20H%3B%20|mb|p|mb|3N|an|4%2B%20S%3B%207-11%20total%20points%20|mb|p|mb|p|mb|p|pc|H4|pc|HK|pc|H2|pc|H8|pc|D2|pc|D9|pc|DK|pc|DA|pc|DT|pc|D4|pc|D7|pc|D5|pc|H9|pc|H5|pc|HT|pc|HA|pc|D6|pc|D3|pc|D8|pc|DJ|pc|S4|pc|S3|pc|SJ|pc|S5|pc|SA|pc|S7|pc|S9|pc|S6|pc|S2|pc|S8|pc|SK|pc|SQ|pc|C4|pc|C5|pc|C8|pc|CQ|pc|DQ|pc|H6|pc|HJ|pc|C6|pc|C9|pc|C2|pc|CJ|pc|CT|pc|CK|pc|C7|pc|HQ|pc|C3|pc|CA|pc|H7|pc|ST|pc|H3|

 

I have 7 off the top, can set up 1 diamond, but if I lose a diamond to East, 2 diamonds and 3 spades through my queen might set me before I can get a 2nd diamond or a spade trick. My plan is to keep West on lead.

 

West helpfully takes his ace when I lead a diamond to the king, and pushes another diamond right back. I'm not sure it was right for me to duck this trick - but when I DO duck this and East doesn't overtake and switch to a spade, I figure, hey, obviously East doesn't have the DJ or he would have jumped on it to beat me.

 

Sooo... I get back in, finesse the 8 of diamonds feeling confident of my contract... and it turns out they were 3-3 all along and East had the jack. Pow, down two.

[georgi]

[hv=http://www.bridgebase.com/tools/handviewer.html?lin=pn|Siegmund,~~M29663,~~M29661,~~M29662|st||md|1S36QH8JAD56KC5JKA%2CS2JAH479D3TAC678T%2CS578TH5QKD248QC9Q%2C|rh||ah|Board%203|sv|e|mb|1C|an|Minor%20suit%20opening%20--%203%2B%20C%3B%2011-21%20HCP%3B%201|mb|p|mb|1S|an|One%20over%20one%20--%204%2B%20S%3B%206%2B%20total%20points%20|mb|p|mb|2N|an|Jump%20in%20notrump%20--%203-5%20C%3B%202-5%20D%3B%202-4%20H%3B%20|mb|p|mb|3N|an|4%2B%20S%3B%207-11%20total%20points%20|mb|p|mb|p|mb|p|pc|H4|pc|HK|pc|H2|pc|H8|pc|D2|pc|D9|pc|DK|pc|DA|pc|DT|pc|D4|pc|D7|pc|D5|pc|H9|pc|H5|pc|HT|pc|HA|pc|D6|pc|D3|pc|D8|pc|DJ|pc|S4|pc|S3|pc|SJ|pc|S5|pc|SA|pc|S7|pc|S9|pc|S6|pc|S2|pc|S8|pc|SK|pc|SQ|pc|C4|pc|C5|pc|C8|pc|CQ|pc|DQ|pc|H6|pc|HJ|pc|C6|pc|C9|pc|C2|pc|CJ|pc|CT|pc|CK|pc|C7|pc|HQ|pc|C3|pc|CA|pc|H7|pc|ST|pc|H3|]399|300[/hv]

[barmar]

GIB's defense can be very mysterious, it all depends on what hands show up in its simulations. So sometimes the simulations hit the mark and it finds the killing switch, other times it goes wrong.