Under what condition can a bowl resting against the jack in the ditch be considered a live bowl?

A bowl resting against the jack in the ditch can be considered a live bowl when it is partly on the green and overhanging the ditch. This condition indicates that the bowl has not completely left the playing surface, maintaining its status as in play. The regulation regarding bowls in the ditch highlights the importance of the bowl's position: if any part of it extends over the edge of the ditch while still being on the green, it is deemed live as it is still accessible for subsequent play.

In contrast, the other conditions mentioned do not meet the criteria for a bowl to be live. For instance, a bowl that has touched the mat line, or one that has struck another bowl first, or exists in a scenario where no other bowls are present do not sufficiently ensure that the bowl in question remains playable or active in the context of an ongoing frame. Understanding these nuances is vital for officiating correctly in bowls.