Interesting Slam Hand. How to get there?

East has a 1♠ opener.

South will pass.

West now has a choice. 4♥ is probably best to show a game going hand 4+ trumps or 4NT (which is risky as it may be too high - need at least 2 key cards) or 2♦ to clarify what is East type of hand East  has.

After 4♥ East is very interested in slam, his hand is far stronger than 12 HCPs. Using the Kaplan hand evaluator  = 13.45 and the weak ♥ s can be trumped. So East will use RKCB 1430 and bid 4N.

West will show 2 KCs and Q trumps by bidding 5♠ and East will raise to 6♠. Easily making with only 26HCPs.

The power of a preempt. Here is a good article on them https://kwbridge.com/3bids.htm

Position 1 and 3 are great places to pre-empt. Do not preempt in position 4. In position 2 there is the good probability that partner has points as opponents have passed.

The vulnerability NV versus V also supports bidding.

With 6+ (7 here) ♣ s a 3♣ bid makes it difficult for the opposition to bid.

South would have opened 1♥ or overcalled 2♥ but does he bid now? 13HCPs ( stronger than this with As and Ks Kaplan hand evaluator shows 14.5HCPs) and no values in the preempt suit suggests that partner is more likely to have support so 3♥ is a good bid.

West knows partners hand. He is unlikely to have 4♠ as with a 4 card major he is less likely to preempt. So should pass.

North has 10 HCPsand 4 card support so should he invite? His 10HCPs are weak with Js and Qs Kaplan hand evaluator which comes out as 8.65HCPS so should pass.

The opening 3♣ will have stopped many NSs finding 3♥ s or going onto 4♥ s going one off.