Sometimes the final bowl offers more risk than reward. You may not have to deliver it, but the choice must be made clearly and at the right time.
The law in one sentence
World Bowls law 25 says the last player to play in an end is not required to deliver the final bowl. The player must tell the opposing skip or, in singles, the opponent before the process of deciding shots begins. The decision is final.
Say it before anyone scores
Do not let teammates begin grouping bowls or reaching for a measure while the choice is still unclear. State plainly that your final bowl will not be played; wait for acknowledgement, then move to the normal shot-count procedure.
When might it help?
An unplayed bowl may be sensible when your side already holds a valuable count and a missed attacking bowl could open a path or disturb a favorable head. The calculation changes with the scoreboard, remaining ends and your delivery confidence.
When should you still play?
If the side needs more shots to win, has a safe positional option, or must defend against a likely count, the final bowl may be valuable. Decide from the head and match situation, not from a blanket rule that the last bowl is always optional.
Source: World Bowls Laws of the Sport, laws 23 and 25. Check your national regulations and event conditions before a competitive game.
Make the call aloud before deciding shots starts; after that, the opportunity has gone.
For a shared view of close heads, try WGTS for iPhone or WGTS for Android. Use the official measuring procedure whenever your competition requires it.