The TAB is facing a loss of more than $500,000 on one single promotion if Well Written wins Saturday’s NZB Kiwi at Ellerslie.

And it stems from the TAB’s desire to bring customers along for the ride, after signing the superstar filly to its slot for the race.

Well Written will start one of the shortest-priced major-race favourites in recent New Zealand thoroughbred racing history if her $1.20 final-field quote holds for the $4 million race.

But plenty of TAB account holders were gifted the chance to back her at $6, even after she had demolished her opposition in the New Zealand 1000 Guineas in November.

Well Written was the $2.30 favourite for the NZB Kiwi after winning the Guineas on November 8 and soon after, she was signed to the TAB slot for the NZB Kiwi.

That prompted the TAB to open a promotion where TAB account holders could back her at her pre-Guineas price of $6 for a maximum bet of $25.

Over 4000 customers took advantage of the promotion and if Well Written wins on Saturday, the TAB will cop that bleeding nose – as well as paying out plenty of other futures multis that could be ending on her.

“She was $6 before her 1000 Guineas win but we quickly changed that to $2.30 after her dominant Riccarton victory,” Nick Conway, the TAB’s general manager of trading, said.

“When we signed her on for the TAB slot, we wanted to give everyone a second chance at the $6 odds, and we look almost certain to pay out the half a million on Saturday.”

But the TAB is unlikely to put up the early white flag as it famously did on Karaka Millions night two years ago.

The TAB paid out early on Legarto winning the $1m Aotearoa Classic for which she was a $1.30 favourite, a smarter-than-it-sounds tactic as many punters take the early payout and reinvest it at the same meeting, increasing turnover and often handing some back to the bookies.

The only problem was that Legarto was beaten into second behind Desert Lightning – so the TAB paid out on two winners in the same race.

The gambling agency isn’t planning to be quite so generous this weekend, so the punters who got the $6 for Well Written will have to watch and wait like everybody else.

With Well Written so hot for our richest-ever race, the TAB bookies have already opened markets without her in them as well: another market also without second-favourite Belle Cheval in the betting.

“And we will be opening a range of other markets on the race, as well as all the normal options,” Conway said.

Michael Guerin wrote his first nationally published racing articles while still in school and started writing about horse racing and the gambling industry for the Herald as a 20-year-old in 1990. He became the Herald’s Racing Editor in 1995 and covers the world’s biggest horse racing carnivals.