I did another 50 deal simulation, same constraints. I apologize for not knowing how to take the hands from DealMaster and plug them into this forum, and I am NOT going to copy them manually
This time, I considered whether 6
♦ made, as well as 6N. Interestingly, there was one hand on which 6N makes but 6
♦ fails. As one would expect, however, there were more hands the other way: 6
♦ makes but 6N fails.
This suggests that I was wrong to reject 5
♦.. but the issue is not as clear as the statistics say, because some of those hands were such that (I think) 5
♦ would have ended the auction, and so we would have got a worse score (by an imp or by a lot of matchpoints) had we bid 5
♦, making 6.
And some of the slams that go down would be slams where I suspect a lot of players wouldn't have bid 4N as responder: some pretty weak looking 15 counts.
For what it is worth, with no subjective bidding assessment (i.e. I allowed all of the hands to bid 4N);
23 hands were cold in either slam
7 hands made 6
♦ but not 6N
1 hand made 6N but not 6
♦
1 hand was cold for 6
♦ but I couldn't predict the result in 6N
1 hand was cold for 6N but I couldn't predict the result in 6
♦
2 hands were such that I couldn't predict the result in either slam
15 hands went down in both slams.
So this more detailed analysis confirms that it is best to bid towards slam as opener opposite 4N... it suggests that moving via 5
♦ is a slight winner... bearing in mind that in my view 5
♦ would not lead to the (cold) slam anyway on some of the 7 relevant hands.
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari