nullve, on 2020-July-09, 15:35, said:
Yeah, this is the layout that I determined as well. Minor variations are possible, West could have KJ
♥. But, if West holds the KJ
♥, there really isn't any defense, so we have to dismiss it.
The Q
♦ and J
♦ could be swapped, leaving diamonds up to somewhat of a guess. Are they 2-2 or 3-1? Are clubs 4-4? Leading the spade fails when West has the K
♥. (West absolutely can't have the A
♥).
So, I think it's worth giving some consideration to the 10
♣. Declarer can't play spade themselves, and still needs to get diamonds right, and the threat of South winning a third round of clubs is looming large.
That being said, partner could have QJ
♠, so, I'd still prefer a spade exit, since a club loses to almost all layouts where declarer holds the Q
♦.