I also agree that they will not due to the full on market BB.It...

I also agree that they will not due to the full on market BB.

It doesn't represent the best return on capital for shareholders in circumstances where the company is now paying tax and accumulating franking credits.

If they spend NPAT on the buy back, it will result in franking credits becoming trapped in the company (which is what the off-market BB would have been able to solve)

Those franking credits are worth significant amounts in the hands of shareholders (i.e. approximately 30% more than the actual cash distribution).

The best approach is probably to keep the BB ticking along at a very slow clip, so that it provides some continuing support for the share price during periods of market volatility, and scoops up more shares out of 'weak hands' which might help result in a more stable share price in future. But buying back another 200 million shares (requiring the expenditure of more than $2 billion of NPAT at current share prices) would not be a good use of capital given that it would result in approximately $600 million worth of franking credits being trapped in the company.