首先这是一个主从复合句.如果当初Jack进了那个球,我们就赢了.
主句We would have won; 条件状语从句if Jack had scored that goal.
主句是一个主谓结构的句子.主语We,谓语would have won,没有宾、定、补,其状语由if引导的条件状语从句担任.
条件状语从句是一个主谓宾结构的句子.从句主语Jack,从句谓语had scored,从句宾语that goal,而这里that可以理解是goal的定语.