Log positions when points are even?

I noticed the Reds and the Waratahs, curently both have 21 points but the Reds have a points difference (PD) of -53 and the Waratahs have a PD of 2. This would indicate to me that the Tahs have a better performance ratio in that they have less points scored against them and more points scored for them than the Reds do. That being the case, how is it then that the Reds are placed ahead of them in the log standings? Can someone please explain how this works...

I actually don't know how the tie break works.

But if you look, Reds have more wins. That would be my first guess.

Next tie break might be head to head. I don't know this for sure though because it's my first Super Rugby season I've watched.

Does anyone know how the points system work?  Seems a bit unfair the way things stand at the moment...???