For all the bells to be sounded exactly where and when they should be requires very close teamwork among all the ringers in the band. Since a bell sounds about three quarters of a second after the ringer has initiated the pull, achieving correct striking requires the development of reliable internal rhythm, fine attunement to the actual sound of the bells, and the ability to interpret the visible movement of all the ropes in the circle.
The changes in the order of the bells' sounding constitute a method that is governed by four rules and one ideal. The rules are that: (a) each bell sounds once in each row; (b) no bell may move more than one position at each change/row; (c) no row is repeated; and (d) the ringing begins and ends in Rounds.
The diagram at right shows the simplest of the methods, Plain Hunt, on four bells with a line drawn through the path–that is, the sequence of moves forward and backward in the order–that is followed by Bell #2. So, in the first row the bells ring in order 1234, then in the next row adjacent pairs of bells all switch positions and the order becomes 2143. In the next row, the bells in the first and last positions remain in place and all the others switch producing the new order: 2413. Such switching continues until the bells come back into Rounds.
Courtesy of the National American Guild of Change Ringers.
For further study, refer to the academic references page.