GIB notations

[queenk]

On each board played there is an option along the bottom "GIB. When this is activated there are notations such as: "=", 1, perhaps 1 in red, maybe 2 or 2 in red. I think they are indicating the card the robots feel is the correct lead in the suit you have chosen. Would appreciate an explanation.

[DavidKok]

I think you are referring to the double dummy analysis? If so, it is showing the number of over- or undertricks that will be made with optimal play after selecting that card.

[nige1]

On each board played there is an option along the bottom "GIB. When this is activated there are notations such as: "=", 1, perhaps 1 in red, maybe 2 or 2 in red. I think they are indicating the card the robots feel is the correct lead in the suit you have chosen. Would appreciate an explanation.

GiB shows the result at double-dummy (perfect play seeing all 4 hands)

if you choose to play the designated card.

• = (Equals) means the contract makes.
• Numbers indicate undertricks (red) or overtricks.

[mycroft]

To be clear about the numbers:

 

= means that if this card is played, nobody can do better than making provided everyone plays perfectly(*) thereafter.

1 in green means that if this card is played, the perfect play result is making with one overtrick.

1 in red means that the perfect play result from that play is down one.

bigger numbers should be obvious.

 

(*) "Perfect" means "everybody looks at each other's cards, and *knowing everything* makes the best play at every opportunity". That does not mean "best percentage play" - if you have to make a first-round finesse against the 8, you'll know to do it. That does not mean "best systemic play" - if you have to underlead your ace so partner gets the third round ruff, or play the 7 to unblock (even though that's a "discouraging signal", you'll do it. This is also known as "double-dummy play" - because if there are two dummies, you know where every card is.