> ## Documentation Index
> Fetch the complete documentation index at: https://docs.screenshepherd.live/llms.txt
> Use this file to discover all available pages before exploring further.

# What it will never do

> The promises ScreenShepherd makes about your service.

A slide that comes up too early is much worse than one that comes up a moment
late. Everything about how ScreenShepherd behaves follows from that.

## The promises

<CardGroup cols={2}>
  <Card title="It never goes backwards" icon="arrow-right">
    ScreenShepherd only ever moves forward. **previous** is yours alone.
  </Card>

  <Card title="It never goes past the end" icon="square">
    It will not run off the end of a song.
  </Card>

  <Card title="It waits when it is not sure" icon="ear">
    If it is not confident, it does nothing and lets the slide stand. A late
    slide, not a wrong one.
  </Card>

  <Card title="You always win" icon="hand">
    Anything you do takes over immediately.
  </Card>
</CardGroup>

## What this means on a Sunday

**Nobody needs to sit watching it.** It is not something to supervise. If it is
unsure it stops moving, and a slide sitting still is something you would notice
anyway.

**You can take over at any moment**, without stopping it and without warning
it. Press **next** in ProPresenter and it comes with you.

**Stopping it never stops ProPresenter.** Press **stop** and you are simply
back to running the service by hand, exactly as before.

**Sometimes you will press next yourself.** Usually when the band is going
round a chorus again. That is it choosing to wait rather than guess, and it is
working as intended.

## About song changes

It can only choose from songs in your playlist or library. It cannot invent
one.

Any song change it makes can be undone straight away with the **go back to**
button, and once you have overruled it, it will not try that song again for a
while.

## What it cannot do

Two things worth knowing:

* It cannot tell apart two songs that share the same chorus.
* It cannot follow a song that is in neither your playlist nor your library.