Making the Right Call

At the table, sometimes we are at the cross road and do not know which call is the best.
Let's see what you would do with this hand.

West  ?	North	East 2 1	South 2	Board 2 IMPs N-S Vul	North
				2  J 9 7  K 9 2  Q 9 8 5 3 2
1. Preemptive

Think about what you would do before reading on.









Basically we have a few options here:
1. Pass
2. 3
3. 4
4. 5


1. Pass
Game is already out of question.
NS are given maximum bidding space to explore their slam.

2. 3
Game is already out of question.
NS are given sufficient bidding space to explore their slam.
3, 4 are natural and forcing.
4 is a hand that worth playing in game.
4 is a better raise than 4, showing at least mild slam interest.
If South bids 4 after 4, North can make another round of slam try.

3. 4
5X is about 500-800 according to the preemptive style.
This bid may not be widely accepted, but technically the best bid, as most of the time East is not allowed to raise the preemptive bid.
NS has about 25+ HCP and likely 9+ cards spade fit.
Their 4 is cold and they are still allowed to bid it. Therefore, they are likely to bid their game instead of making the penalty double to 4.
4, 5 are natural and non-forcing.
Their slam try methods are greatly reduced to 5, 5, or start with double.
Most of the time North has to choose between 4 and 5, which some of the time he can never be correct.

4. 5
5X is about 800-1100 according to the preemptive style.
Offering NS an easy 800 is always incorrect, they do not need to bet on anything to penalize you.
They should know that they have +650, but not sure whether they can have +1430.
At their point of view, accepting +800 is always a good strategy.
Therefore, this bid is a losing bid.