Generally, the BWS requirements for initial constructive defensive actions (takeout doubles and overcalls) are moderate, but two-level overcalls are sound. The vulnerability somewhat affects the minimum strength required.

• 一般而言,BWS对于加入竞叫(技术性加倍或插叫)的基本要求是中度牌力,但二阶插叫就要更好一点。所保证的最低限力量多少也会视局况情况而定。