Here is one such hand. You could open 1♠ or 4♠. Other options really aren’t viable, although pass might work out.

 

In making your decision the first consideration is the vulnerability. Here if you open 4♠ and are wrong undertricks are -100, and more if doubled. A certain bad score. The 2nd problem with 4♠ at the vulnerability is the opponents are more likely to bid at the five level with some distribution. They have three chances at being right:

 

1. It could be right if it is there hand making, or

 

2. It could be a profitable sacrifice, or

 

3. Bidding could push you to the five level, going down.

 

1♠ is the right bid. You don’t have to commit yourself and you can listen carefully to what the other three players are saying.

 

Here the bidding continues as follows, giving you another decision:

 

Sounds like partner doesn’t have much, but maybe long diamonds. If they bid 3NT you will not be able to beat it if they have two spade stoppers, as you have only one entry. The best chance is try and buy the contract for 3♠, or at least it may derail them from bidding 3NT, a bid you do not want to hear.

 

The full deal: