Ilya , I modified your suggestion to not include the 5 level. Is that OK ?
 
2008-01-07 06:24
 
Hand Evaluation – Doubles ( captaincy )
 
PITBULLS:
 
            Once you have described your distribution & limited hand to partner & she doubles the opponents , captaincy rules apply when forcing pass theory does not apply. She knows more about your hand than you do of hers , so the double is trump stack penalty. In our system , we have discarded  “up the line bidding” in favour of showing our distribution. We rebid 1NT with a balanced hand so if we bid a suit , we are showing distribution. We are describing our hand to partner ,  so partner knows what to reasonably expect. Therefore , trump stack penalty doubles apply in auctions due to captaincy considerations where we do not necessarily own the auction. This is why pre-empts or pre-emptive bidding are an exception to D.S.I.P. theory. Partner is always the captain opposite a pre-empt , so she has trump stack penalty double rights.
 
A 1-P-2-2♠
    4-4♠-P-P
    X                       should be penalty based on captaincy considerations.
 
            Take this auction for example. Everybody vul ,     
 
1♣-1-1-P
1♠- 2/3-X   . Opener has described 9 or 10 black cards so what more is there to say ? There are no unbid suits left , so a double to clarify responders hand is meaningless as partner has already described her hand. Responder is an unlimited captain of this auction , so she has rights to make a penalty double. There is no reason for a D.S.I.P. double as distribution around the table is a known factor.  Also , there is no hint of competing as responder is unlimited. Whether responder is unlimited should have an effect on D.S.I.P. double theory. There is a school of thought that a double by an unlimited hand should be co-operative penalty rather than an offensive hand type.
 
    
             
            In keeping with the captaincy concept , a NT rebid is an unambiguous auction. You do not need a D.S.I.P. competitive double to clarify things , as the 1NT rebid is quite descriptive with a tight range.
 
1♣-1-1-P
1NT-2-X          By virtue of the 1NT rebid & responders unlimited status ,  we have transferred captaincy to responder. Therefore , the double of 2is for penalty.
 
            Quite often these “captaincy doubles” adhere to the over/under rule. We are behind their suit when we make our trump stack penalty double. Anyway , the double is penalty as partner has given us enough information for us to do our dastardly deed. As with pre-empts , partner has already described her hand , so captaincy enters the picture. Trump stack doubles are not totally dead in these auctions.
 
            The most common “captaincy” situation in Bridge is a simple raise of a major with opener bidding or jumping to game. If the opponents now interfere belatedly , opener is captain as obviously she knows the situation better than you do.  A double in these situations can be of the forcing pass variety if the previous auction deemed it to be such . However , if the auction was not competitive or forcing passes not involved , captaincy should apply rather than D.S.I.P. doubles. You need a truly competitive auction for D.S.I.P. doubles to apply. Ilya Kuzkin advises to modify “captaincy” in favour of D.S.I.P. competitive doubles as long as the rank of their suit does not force the auction to the 5 level. This means that without active competition in these simple major raise auctions , a double of 4♣,4 & 4 is D.S.I.P. , however a double of 4♠ would be penalty as that forces us to the 5 level. With active competing up to the game level , even a double of 4♠ is D.S.I.P. though nv vrs vul.
 
         Along with the same theme of no “up the line bidding” , Tom Gandolfo has some ideas for 1♣-P-1auctions where they bid in the sandwich. Since we do not play up the line bidding , how do we show good balanced openers without a stopper in their suit after they have bid in the sandwich position ? Tom  suggests playing a double to show balanced hands without a stopper in their suit . Since we do not bid a major with a balanced hand , Tom says use a double to show these hands. Tom suggests a pass would only be made when holding their suit & waiting for a re-opening double to convert for penalty. A 1NT rebid of course , shows a  balanced hand with a stopper in their suit.