[001hans]

Nobody mentiones the 3♣ bid. I guess 2♣ may also be bid on a 4-card suit (say xxx, xx, AHxx, AHxx). So the correct rebid after 1♥ - 2♣ is 2NT. Now N bids 3♣, showing length. South 4♣, agreeing trumps. Neanderthal or homo sapiens, any North would now bid 4♦. After that missing slam is out of the question. In the given sequence, up to 3♣, what can possibly be wrong with 4♣ ? Even if showing second controls (kings, singletons) is beyond agreements, a 4♣-bid, followed by 5♣ after South bids his ♦Ace, tells South that he has useful values besides long and good clubs.

[benlessard]

In a vacuum if we keep only the hands where club is trumps and remove hand because of lead directing X and because of leaked informations a 5C bid should be under the bottom 5% range of hands. This is because there is at least 20 ways to reach 5C and jumping to 5C is the weakest of them all. In practice I tend to bid 5C with the bottom 5-7% (1/20 or 1/15) of my 2C on hands that ive decided that 3NT/4H is out.

Qx
x
Kxx
AKxxxx

look to be close to be the average hand. Wich lead 5C to be a gross underbid. Fast arrival is one the most misunderstood concept in bridge, I always need to repeat to my students that it doesnt show a minimum hand it show an ugly duckling hand amongst the minimum hand. Fast arrival is an exceptionnal bad hand when you have a lot of space available and should be used rarely. I think the confusion is cause because most players are taught that cuebid show extras without the distinction of partner being limited or not. Also most case you dont have that many space available so the ratio can be quite different.

There is a huge difference in

1S-2C-2D-4S
and
1S-2C-2H-4H

in the first case after 2D there is a huge number of sequence that lead to 4S starting with 2S. So 4S should be used for very rare hand type (fast arrival or picture doesnt matter). In the 2nd case there is a lot less ways that lead to 4H (starting with 3H) so the 4H bids requirement have to be lowered. Sure in practice we cannot defined all the bidding space that we have and there is a cost of making slam tries. But its an example to show that in some situations where you have a lot of spaces people tend to jump way too often.