Relay Precision vs Natural

Let's take a hand from the 47th European Bridge Teams Championships, Open Teams, Round 18, Sweden vs Italy

Board 3. Dealer South. E/W vulnerable

-------S 8
-------H A Q J 6
-------D K Q
-------C A K J 8 5 4

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

-------S A Q J 7 3
-------H 10 8
-------D 10 8
-------C Q 10 7 6

The bidding in the open room went:
West North East South
Duboin Bertheau Bocchi Nystrom
-------------1S*
P - 2C* - P - 2H*
P - 2S* - P - 3D*
P - 3H* - P - 3NT*
P - 4C* - P - 4H*
P - 6C - Allpass

Unless you're a fan of Peter Bertheau-Fredrik Nystrom, you will need the following:
1S: 10-15 HCP, 5+S, usually not 5332 10 hcp
2C: GF, relay
2H: 5 card S, minimum, no shortness
2S: Relay
3D: Any 5422
3H: Relay
3NT: 5-2-2-4
4C: asking for top cards, using zz point responses. A=3 K=2 Q=1
4H: one Ace, two Queens

Well done Sweden for bidding the slam. Now the closed room:

West North East South
Fredin Lauria Lindkvist Versace
-------------P
1S - X - P - 1NT
P - 3C - P - 4S*
P - 6C - Allpass

South passed as we would normally do, and West opened 1S. That did not sound like a good start for going to slam, but we have Lauria and Versace here. A jump rebid in clubs, a jump to 4S (presumably a fit jump, with good spades) and a leap to 6C was all they needed.

Push board.

Moral of the story?
You can find your slams without modern machinery, stay natural and spare yourself from the memory work.