When an edit is made on a cut, there is no difference between an “Insert/Overwrite Before Transition” edit and an “Insert/Overwrite After Transition” edit.

However, when the transition contains a dissolve or wipe, editing before or after the transition does make a difference. The following illustration shows what happens to the dissolve when you insert Clip C before the cut between Clip A and Clip B.

After inserting the clip, Clip B and the dissolve are moved after Clip C. The dissolve takes place between Clips C and B.

The following illustration shows how the dissolve is affected when you edit Clip C to the timeline after the cut between Clip A and Clip B.

After inserting the clip, Clip B only is moved after Clip C. The dissolve takes place between Clips A and C.