Use TNT Rule while Competing
Guru: Yes. Too big a fit not to bid 4♦ but doubling 3♥ is an option, with three certain tricks and the ♦A a possible but not certain trick. The Total Number of Tricks (TNT) Rule says ten trumps equals ten tricks. That is making a decision the simple way. By the way, I would open the North hand 1♠ and then rebid hearts as long as necessary.