New rugby union scrum rule has unexpected consequence

Rugby's new scrum law could simply see the crooked feed replace the collapse as the source of contention, and penalties, if the first outings at test level in the Rugby Championship on Saturday were anything to go by.

The International Rugby Board (IRB) introduced the law with the aim of making the game safer for front-row forwards and are hoping for fewer scrum re-sets and the resultant, often apparently arbitrary, penalties.

The law requires the front rows to be engaged and the scrum steady before the ball is put in, removing the "big hit" of the packs coming together and promising a more stable set piece.

The first test of the law at a set piece at international level came after 10 minutes of New Zealand's 47-29 victory over Australia at Sydney's Olympic Stadium on Saturday.

The first effort collapsed just as surely as it would have under the old laws and at the reset, Wallabies scrumhalf Will Genia was penalised with a free kick for not putting the ball in straight.

The straight feed has long been a law more honoured in the breach but confusion reigned when All Blacks scrumhalf Aaron Smith was allowed to get away with a similarly crooked introduction of the ball at the next scrum.

South African referee Craig Joubert ruled a crooked feed for about a third of the scrums, leaving Wallabies coach Ewen McKenzie to describe the set piece as a "lottery for both sides".