[suokko]

I just saw one of those weird looking singleton leads from gib. I started wondering what could make gib to see that lead as most likely way to set 3NT.

After a short moment I have started to suspect that gib might not take into account partner's passes when simulating the hand. For example pass over 1NT limits a lot chances that singleton lead would be the setting lead because many hands with long good major would have bid. But if the simulation code doesn't check hands to be consistent with passes in auction then that would sometimes give huge probability advantage for singleton lead against 3NT.

Of course I can't know if that is the reason why simulation seems to favour singleton leads a bit too much. But if that is the case then it should help many situation where gib does simulations after some passes if there was filtering code to remove hands that don't match passes in the table.

[FM75]

Face to face my partner failed to make a singleton lead in my suit. It was the only winning lead. 4th best was abysmal against ops that had bid suits before settling on NT. I needed two leads of my suit to set up the suit and had two entries. By the time I got to play the second entry, the running suit was exhausted.

If you passed twice, GIB presumably leads against the most probable (or better, we hope, most profitable at the form of play). It might be that a singleton was the best lead.

Guessing on that part.

[suokko]

FM75, on 2014-April-14, 17:51, said:

If you passed twice, GIB presumably leads against the most probable (or better, we hope, most profitable at the form of play). It might be that a singleton was the best lead.

True. I'm not actually claiming that singleton leads are bad in every case. I do them my self against 3NT too. But in my option frequency of GIB leading singleton is a lot higher than winning frequency would be. I also created hypothesis that GIB actually doesn't read accurate meaning of pass when generating hands for the lead simulation.

I actually tough for long moment if my view might be worse than what GIB does in table. But my conclusion was that in this case GIB does worse than I do.

[steve2005]

funny if you overcall a suit GIB wont lead your suit with a singleton but if you pass it might lol