LEARNING CENTER

Dbl. Letting the opponents play in a 2-of-a-major fit is bad bridge. Might you get doubled and go for your life? Occasionally. Pushing the opponents to the 3-level is worth the risk. You might also find a making spot your way some amount of the time. 

4. In the words of the great Marty Bergen, "Points Schmoints." Bidding 4 over 4 is one of life's great joys. There are many ways it could work; you might make. You might go down less than the value of the opponent's making game. They might compete to the 5-level and go down. 

There is a big way you could lose: no one makes anything. Still, the odds favor bidding. I would do it with even less offense than I have here (I might even bid 4 if you turned one of my little spades into a little heart). 

Something showing both majors (conventional). I don't love conventions, but being able to show two-suited hands after their notrump can be invaluable. I'd rather not emphasize only spades (though I would if I had to). This is not the same situation as Michaels cuebids or unusual 2NT. Because we can play on the 2-level, we do not have to be 5-5 in our suits. 

Pass. Who has the spades? Partner could have overcalled some number of spades with spades. Maybe East passed with five or six small spades and two count. Balancing is very dangerous as the opponents may find a better scoring spot (including 4). 

Dbl. Your hand doesn't have enough offense to compete to the 5-level. Partner is unlikely to have three aces, which means if you picture partner with something like 

 Q8  
 AQJ  
 A876  
 8532, 

You have to lose a spade, and at least one, quite possibly two clubs. In four spades, you'll usually find a heart or two, a club or two, and a few diamond tricks.

3. Don't give the opponents time to discuss where they belong. You have no defense against a black-suit contract and lots of offense via your values in your long suits. You might not make 3, but they might be making 4 on the right layout. 

Dbl. Yes, we have a fit, but we don't really want to compete to the 5-level without extreme shape. This is not a "penalty" double, it says "I have the value to compete and I don't know what to do." That's an accurate description. If partner has a normal opening bid, he'll pass. With something like 

 -  
 AKJ765  
 K2  
 A9765, 

Partner will bid on.