Here the bidding shows why the Jacoby response should be used with at least 4 trumps: because you make the responder hand the base hand, reaching easilly 7 (althou I guess splinter might end up there also, but probably not as sure).
Scoring: IMP
S - N
1♠-2NT
3♦-4♣
4♥-7♠
S - N
1♠-2NT
3♦-4♣
4♥-7♠
We had some missunderstanding on the bidding (* showed majors for one, and hearts for the other), but the contract wasn't that bad, after a ♦K lead I ruffed in dummy, cashed ♣A+♣K West discarding a ♦, after that I played to assure only 1 off, but I missed a line that would had made as the cards lied, can you see the winning line I missed?.
S - N
1♠-2NT
3♦-4♣
4♥-7♠