Snap Dragon Doubles
After pard has overcalled and RHO bids a 3rd suit, double says:
1. You have the unbid suit
2. You have tolerance for your suit (named in the overcall)
It can be quite useful, at least until someone comes up with a better usage
for the bid. In terms of frequency of use (cost), it does not interfere
with anything except those oppomnents who use negative free bids,e.g. that
bid of 3rd suit not forcing (and you wish to make penalty double).
One has to have a hand commensurate with the level you are forcing
partnership to rest. For example:
1C - 1H - 1 Sp - Dbl forces partnership to 2 level
1D - 1 Sp - 2H - Dbl forces partnership to 3 level
etc.
Source:Harold Simon (from e-mail sent me on discuss@OkBridge.Com)