A few theories around
1) he saw the writing on the wall at Yorkshire as the squad was in decline/England call ups biting even deeper
2) he wanted to go back to Oz for more family time- so has he got fed up of the family?
3) expected to be offered a big job in OZ- didn't materialise. He was in charge of Australia A but their wage strike meant he never got to display his skills on the international scene so no progress for him
4) He had a big fallout with Wensleydale Creameries- Yorks main sponsor- thought they were too demanding of squad time so maybe he burnt his bridges because of that.
In further news ex Yorks bowler Chris Silverwood now in chaqrge of England bowlers and Anthony McGrath subsequently made head coach of Es*** today- grooming him for a return one day?
There will be a lot of pressure on Andrew gale this season and a good start is *****. Could be difficult if Ballance has a good winter and ends up with England next summer.