♠ QJ965 ♥ AKQ54 ♦ 93 ♣ A

After opening 1♠ you get 2♣, almost any gf, you bid 2♥ and get 3 ♠ 

2♠ being Meckwell slamish, in either major, you try 4♣ and get 4♦

Now road is open to kcard asking and u get 3 keys!

Any minor K will be gold, but grand can still happen with no minor K from partner

Still You bid 5nt and get the annoying 6♠, no minor K

What do you think the grand slam chance became?

To tell the truth this auction would be possible with my regular partner, with an ocasional, I knew he had 4+ ♠ and probably no shortness, how does this gets better odds for the grand?