At first glance, does your contract look lay-down? In that case, double up your attention and prepare for the worst.
Dealer South. All Vul.
You are South and you hold 23 balanced:
How do you open this hand?
With a strong 2♣️ of course. North answers 2♦️, a relay. You rebid 2NT and partner jumps to 6NT.
West leads the club eight and the dummy comes down:
Contract: 6 No-Trumps.
Lead: 8 of Clubs.
How many top tricks do you have?
Four Hearts, three Clubs, two Spades and the Diamond Ace are ten immediate tricks from the top. You need two more.
Will you easily make your contract?
A priori yes, because in order to make your small slam, all you need is that your nine cards in Diamonds:
yield two more tricks together with the Ace.
Unless all four missing Diamonds (K1098) are in the same hand (a 4-0 split is not so rare, since it does occur in 10% of cases).
How can you find out?
That’s easy. Win the opening lead in dummy, call for the Diamond 2 and see what happens: