At least some content in this article is derived from information featured in Harry Potter: Hogwarts Mystery. Spoilers will be present within the article.
Bumphing is a common Quidditch foul that consists of a Beater sending a Bludger towards the crowd. This immediately halts the game, while officials rush to protect fans who are watching the match. Unscrupulous Beaters often do this in order to prevent the opposing team from scoring.
During the first Quidditch friendly attended by Jacob's sibling at Hogwarts in the 1980s, Beater Erika Rath committed this foul; Chaser Skye Parkin, who managed to grab one of the Beaters' bats, saved Jacob's sibling from being hit in the face by the Bludger only just in time, though it cost her team the match.