As Zac Purton prepares to rack up his 1,500th Hong Kong win in the coming days – he is two victories from the milestone – and celebrate his 40th birthday on January 3, there are mathematically sound grounds for arguing he is riding at the peak of his powers.

Basic calculations show Purton has registered 67 wins from 238 rides at an average of 2.48 victories per Hong Kong meeting in which he has taken part this season – Covid-19 incidents forced the five-time champion jockey to miss two of the city’s 29 cards.

With the Jockey Club authorised to run 88 meetings, even if Purton ends up sitting out another couple of cards between now and the end of this term, he is still tracking north of 200 wins, which is amazing given Joao Moreira’s Hong Kong record stands at the 170 victories he notched in the 2016-17 campaign.

But that is enough of uncomplicated, unrefined, unsophisticated mathematics.

Purton is deserving of a much higher standard of number crunching, a Group One-level of analysis that shows this season is the first season of his Hong Kong championship-winning era in which he is outperforming the betting market.

Based on the starting prices of Purton’s 238 rides this term, his expected wins score is 63, whereas his actual wins score is 67.

The last Hong Kong term in which Purton’s actual wins exceeded his expected wins was the 2011-12 campaign when he saluted the judge aboard 64 horses when the betting market forecast he should have done so 61 times.

In each of the last 10 completed Hong Kong seasons, not even the individual brilliance of Purton could live up to the collective confidence of punters.

In 2012-13, Purton rode 88 winners when punters bet as though he should have ridden 102 winners. In 2013-14, it was 112 versus 119. In 2014-15, it was 95 versus 97. In 2015-16, it was 80 versus 98. In 2016-17, it was 107 versus 116. In 2017-18, it was 136 versus 152. In 2018-19, it was 168 versus 183. In 2019-20, it was 147 versus 176. In 2020-21, it was 125 versus 157. In 2021-22, it was 136 versus 168.

That Purton is outperforming the betting market this term despite the Zac Tax – the slang phrase for the reduced odds associated with his rides – being at, arguably, its highest-ever rate following the departure of Moreira is a remarkable achievement.

Purton, who has a full book for Saturday’s 10-race meeting at Sha Tin, sits on 1,498 Hong Kong wins following his midweek treble at Happy Valley.

At only seven of 27 meetings this season has Purton failed to ride at least two winners, so Christmas Eve is odds on to be the day he joins foundation member Douglas Whyte in the 1,500 club.

Treadmill ready to send fellow Classic Series contenders Packing with Bowman on

It is common knowledge there are conversations in the Purton household about when the man of the house will hang up his riding boots and turn his hand to something else.

He is one of those people who will succeed at whatever he does.

For those of us who derive considerable pleasure from watching him ride winner after winner after winner at Happy Valley and Sha Tin, let’s hope he sticks at the racing caper for a while longer because he is bloody good at it.

The numbers say he is as good as he has ever been.