Further to my email to Unitab I have been verbally informed of the issue of jackpots.
If in a race at Dubbo during the week $10,000 was invested on the trifecta but only 10 % was placed on the winning combination. Unitab withdraws 10 % of the gross pool ( $1,000) and deducts 20 % as commission.The net payout amount of $800 is then distributed to winning punters. If a punter had 2% of the original pool he will now have 20 % of the new pool , so he would receive a payout of $160, another punter with say, 3 %,his payout will convert to 30 % = $ 240 etc
The balance of the original pool ( $ 9,000 ) is fully held over until say, like today, where it would have been added to the pool on race eight in Melbourne. Once added to that pool the 20 % commission would have been deducted. In effect $7200 would be added to the payout pool.
Bubba, that all appears fair enough, we now at least understand what happens so thanks for investigating that.