It Could Have Cost the Match
In the amazing defeat of the Italian team by South Africa, South Africa danced with the Devil on one deal.
Opener held Kxx-AQJxx-KQx-xx
Responder held AQJ10xx-109-AJx-xx
Obviously, 5S is a poor contract. If the heart finesse fails, 5S will likely be set, even on a passive diamond or spade lead. If the heart finesse works, 6S makes if the opponents do not find the club lead. If you are going to gamble, might as well blast. But, prudence is called for.
The South African auction:
2S-P-4S(mild slam try)-P-
This sequence not only landed South Africa at the five-level. It also directed the defense. Fortunately for South Africa, the heart finesse worked.
A better auction would be to use the "other major" as a slam try. Responder transfers, and then he bids 3H (three of the other major) as a slam try. When someone declines to cuebid clubs, a signoff results and all is well.