Timkin

why not 3♦ - 4N (RKBW) 5♠ - 7N Responder can count 2♣, 7♦, 2♥, 2♠

What do you do after you open 1♣ and opponents bid and raise ♥ ? or even ♦? With two short red suits, it is highly likely the opponents will easily find and bid one. Opening 1N forces the opp to bid at the 2 level - so not so likely. 1N also defines your strength for your partner immediately. If you play a NT contract it is right sided with the 2 kings.

The best way for a regular partnership is to use an expert tool called Serious 3N after a confirmed M suit fit is establish - the 2♠ bid shows a limit raise or better. Serious 3N is a "non-specific cue bid" asking partner to cue bid his lowest control (A or K) - this allows opener to locate the hardest control to find - the K of clubs! With this agreement, a cue bid of 4♣ promises BOTH the A and K - so not worried about clubs When responder bids 4♦ - denying the ♣ K, opener knows he may have a ♣ loser and can stop in a safe game contract with his 5 loser hand.

oops -- I meant that 3N does NOT convey the playing strength!

With the absence of any interference, I would be more concerned about missing a slam than game! If 3C is not forcing, and 2D is not accurate description of hand, 3N is reasonable but does convey the playing strength. 5C is a reasonable contract if P does not have the goods for slam. Unusual hands usually require unusual treatment. Since it is unlikely that P has no key cards, I suggest RKCB. With 1430: P bids 5C ( only 1 KC) -- Pass and hope to make a reasonable game - slam unlikely. P bids 5D -- what? -NO keycards, OK, we may have a wee problem! Where are the opponents ? Have to take my chances at 6C. If that goes down, opponents likely are missing a makeable contract anyway. P bids 5H -- (2 w/o Q) -- bid 6C -- with good chance , may make 7! P bids 5S --(2 w Q) -- bid 5N -- (ask specific K) - give me the Kc- 7N is cold. Am I 'off the wall' ?