The Encyclopedia of Interactive Performance

Sudden change carries impact. When you want change to be surprising or shocking to spects, deliver it abruptly and without warning. Make a left turn.

When talking about something important, a sudden change of topic can make spects wonder why the first topic is being avoided and want to pursue it further. A sudden change of your point of view surprises spects and raises the question of why your perspective has changed. Bad news packs an extra wallop when you deliver it in a sudden left turn.

Gradually building up to something telegraphs that an important change is coming. A one-sentence left turn catches spects unprepared. If you want spects to be taken by surprise, introduce change with a left turn.