Notes
1
It is better, but not essential, to have an even number of couples
2
When reaching the end oif the set in B1 you should complete the turn with an imaginery couple above or below.
3
When standing out, change sides immediately, and do the back-to-back with the approaching couple, but do not join in abything else. The other couple will use you as 'posts'.
4
B2 can be thought of as 'interlocking heys' with the 1s doing a morris hey and the 2s doing a grimstock hey.