[Zelandakh]

mfa1010, on 2014-February-04, 17:12, said:

He doesn't know about the ♣J, though, which is useful when ruffing all those spades.

I could have found out about the ♣J in my auction by relaying one more time - I decided at the time it was not necessary but perhaps it would have been better. Anyone care to calculate the odds difference between East having it or not? It is only relevant if it makes the difference between bidding 6 or 7.

[Cascade]

If East has five clubs and you know about the king then it is exactly 50% that East had the Jack. There are eight outstanding clubs and eat had for of them.

If u you know East had more values the odds go up.

If east may have six clubs the odds go up. Now East has five of the eight outstanding clubs that are not the king.

The precise percentage is difficult if not impossible to calculate as the information we have is never exact.

With no information we can calculate a theoretical percentage:

Prob(5 clubs) × 0.5 + prob(6 clubs) × 5/8 + prob(7 clubs) × 6/8 + prob(8 clubs) × 7/8 + prob(9 clubs) × 1

Prob(5 clubs) = 9C5 × 30C8 / 39C13
Prob(6 clubs) = 9C6 × 30C7 / 39C13
Prob(7 clubs) = 9C7 × 30C6 / 39C13
Prob(8 clubs) = 9C8 × 30C5 / 39C13
Prob(9 clubs) = 9C9 × 30C4 / 39C13

[P_Marlowe]

Pass - 1C
2C (1) - 3NT (2)
all pass

(1) inv. minor
(2) vs. a passed hand the practical bid

I could construct an auction that gets us to 6C, and depending
who is asking, giving us a shot at reaching 7C, but I dont see,
why I should try to construct an auction.

The first decision to take is show the inv. raise with the club
fit, or the secondary suit.
I prefer to show the fit, if we would show the diamonds, we rebid
1NT, now responder should most likely look for a possible safer
game besides 3NT, giving his major suit holdings.

Opening 2NT is ok, but then it depends a lot on methods, and as
opener I dont follow a upgrade into a stronger opening with an
upgrade, that moves me in the upper range of my opening bid.

With kind regards
Marlowe