[miamijd]

 Mkgnao, on 2019-January-10, 04:21, said:

6NT is cold on this lay-out (1♠, 5♦ and 6♣ makes 12 tricks). 6NT in South could go down on a ♥-lead if you misguess ♥, but it is very unlikely for someone to underlead their ace against 6NT so you ought to get them right. Notice that 6NT played from North is cold (without ♣ breaking 3-0 with West having the length).

I disagree with all the comments fiercely criticizing North's second pass having seen all the hands. Assuming double is penalty, give partner ♠AKx, ♥Axx, ♦xxx, ♣Axxx. 4♠ is certainly -1, most likely at least -2. If you bid, partner will go down in both 5♣ and 5♦. The partner of some of the forum posters will go down even more in 6.

Your mistake is "assuming double is penalty." It isn't. It's a good hand that has tolerance for any action partner takes. The hand you provided should PASS 4S and take the plus. If partner can't act over 3S with a likely void, then you aren't going to make anything.

It's far better -- and near-universal expert practice nowadays -- to have the double as cards/takeout (yes, partner will very often leave it in) than to use it as penalty.

Cheers,
Mike