I blew the chance to bid a slam on the following OK Bridge Internet board. I was sitting North, with South dealing and East-West vulnerable:

 

                  NORTH
                 ♠️ A 10 9 7 4
                 ♥️ A K
                  ♦ Q 10 9 8 4 2
                 ♣️ —


WEST                                   EAST

♠️ J 6 3 2                            ♠️ Q 5
♥️ 8 4                                  ♥️ J 10 9 7 3 2
♦ 6 5 3                                 ♦ J
♣️ K 9 6 5                          ♣️ Q J 4 3


                SOUTH
               ♠️ K 8
               ♥️ Q 6 5
                ♦ A K 7
              ♣️ A 10 8 7 2


The bidding proceeded as follows:

South          West          North         East
1NT             Pass           2♥️•          DBL!
Pass••         Pass          3♦•••          Pass
3NT            All Pass

• Transfer to spades
•• Pass shows two spades
••• Second suit 5+ strong

Opening lead: ♥️8

Doubles of artificial bids ask for an opening lead in that suit. Did East really want West to lead hearts?

In any case, we made six for +490, but it was a bad score that netted us -1.50 imps. Nine of the 29 North-South pairs reached a superior 6♦ contract.

Was there any way we could reach that bridge promised land? Let’s table strict adherence to point count. True, I had a 13-point hand, but I should have added three more for the fifth and sixth diamonds and fifth spade. Furthermore, once a fit is established in spades or diamonds, the club void is worth another five points. But the main concern is tricks, not points; and I should have seen real potential here.

Instead of passing 3NT, I should bid 4♦ to show at least six of them and interest in slam. With the ♦A-K in tow, partner would be delighted to take up the challenge.
Here’s a better auction:

South                    West              North                East
1NT                       Pass               2♥️                   DBL
Pass                      Pass               3♦                      Pass
3NT                      Pass               4♦•                    Pass
4♥️/4NT••         Pass               5♦/5♠️•••        Pass
6♦   All Pass

• Forcing
•• Depending on your system, a Roman Key Card Blackwood bid
••• Showing two of the five key cards (four aces, ♦K), plus the ♦Q

North-South pairs who bid 6♦ earned a +920 score and +7.46 imps.