http://www.rpbridge.net/8t69.htm

Board 1

North Deals   S 10 9 3
None Vul      H 9 7 5 4
              D K 10 5
              C 9 8 6

S Q                       S J 7 6 5 4
H A K Q J 10 3            H -
D 8 7 6 4                 D A Q J 9 3
C 10 2                    C A K 5
              S A K 8 2
              H 8 6 2
              D 2
              C Q J 7 4 3

Off to a red-hot start! East-West can make a slam in either red suit,
but it's hardly biddable. A common auction should be:

West North East South
     Pass  1S   Pass
2H   Pass  3D   Pass
4H   All Pass

Some Souths may scrounge a 2C overcall, which should not change the
East-West bidding. West might sense a slam after East's 3D bid, but
the four-card fit is less appealing without an honor. The key to slam is
East having almost all his points outside of spades -- hard to
visualize, unless the Bridge Laws allowed an opening of "one no
spades."

In hearts, 12 tricks are easily made by taking two diamond finesses.
After a club lead, it is tempting to try for all 13: Ruff the third
club, draw trumps, finesse diamonds once and hope they split. Oops; the
price of greed is then only 11 tricks. Been there; done that.

In diamonds, the same 12 tricks are available with careful play (ruff
two black cards, win three hearts, finesse trumps twice) but it is
doubtful many will play there. Even if West stretches to slam, it would
be quite a position to choose diamonds over hearts at matchpoints.