Better refereeing, the only problem is the lack of depth. Gerard Sutton for example in the Tigers/Raiders game was absolutely atrocious and nowhere near first grade standard. Any referee who is unable to recognise a tackle being effected in the lead up to a try, and then having the option to back out of his stuff up by going to the video ref... and STILL getting it horribly wrong, is not worth his salt at this level. Other than lack of depth to sustain it, the game has sped up enormously, much to the detriment of any team who want to sabotage necks for a slow play-the-ball.
