Alternate Bidding Sequence
Suppose that South raises to four spades as recommended:
West’s Call over Four Spades? With good defense, we think that West should double.
East’s Call if West Doubles Four Spades? In our partnership, West’s double would promise at least two big cards, so East (vulnerable versus not) can expect good chances to make a contract at the five level; if that’s possible, then plus 600 and plus 620 will score a lot better than plus 100 or plus 300 against four spades doubled. In many advanced partnerships, a four notrump call by East would promise at least two places to play; West would bid West’s lowest four card suit. East has a difficult decision, and that’s one benefit of South making ‘the pressure bid’ of four spades.
Real World Bridge 5: Competitive Bidding Part Two includes a discussion of high-level competitive bidding decisions in Chapter 3.
You will find a discussion of defending against the opponents’ pre-empts in Chapter 5 of Real World Bridge 5: Competitive Bidding Part One.