Dunn has an unassailable lead in the national drivers' premiership with 173 wins - 74 wins ahead of Blair Orange (99) in second place.
His season's universal driver rating (UDR) of 0.3177, which is worked out through a formula of wins and places divided by starts, is the third-best in the country behind Natalie Rasmussen (0.5837) and Mark Purdon (0.4673) for drivers with more than 50 starts.
But that rating pales into significance when compared to his record at Forbury Park.
Dunn has driven 37 winners in just 12 meetings at the 1007m circuit since his first appearance last season at the early October meeting.
Those 37 wins have come from 103 drives and - once his 18 seconds and 24 thirds have been added in - his UDR at Forbury Park is 0.5339.
Dunn's top night at the track was just last month, when he recorded six wins and three placings in his nine drives on May 22.
So how does his record this season stack up against recent years? His best year for tripping the 4 hours down State Highway 1 was last season, when he recorded 39 wins at the Dunedin track in an overall season tally of 199.
The previous best was his record-breaking season of 2010-11, when 36 of his 220 wins came at Forbury Park.
While there are more racing opportunities these days than even 15 to 20 years ago, the fact Dunn is just three wins away from equalling Ricky May on 240 wins at Forbury Park since 1975 speaks volumes about his impact on New Zealand harness racing.
Dunn was surprised to hear yesterday he was close to knocking May off his perch for the most wins on the track, although he chuckled when it was suggested the Forbury Park record would almost be as good as May's seven New Zealand Cup wins.
Perhaps the secret to his remarkable strike rate is his ability to adapt to the individual scenarios that unfold in front of him every time he drives at Forbury Park.
''Each race is different - there's no certain pattern at Forbury,'' Dunn said.
''There's no certain position to be or anything like that - I've just had the right drives down there lately, which has helped.
''The track's excellent now - since they went to the sand, it's really made the track a nice track. That's why the times have improved so much there.''
Dunn no longer works full-time for trainer and mentor Cran Dalgety, but the association has continued apace this season, with Dalgety providing Dunn with 12 of his winners in Dunedin.
''Cran usually sends a couple down there a meeting, and they've been doing a good job - that helps. Graeme Anderson's team has had a good season, and Brian Norman's.
''The usual guys I drive for have been going well and I've been able to get one or two winners a meeting, so that's been a bonus.''
Dunn is quick to deflect praise on to the horsemen who book him to drive their pacers or trotters.
He is taking a similar low-key approach to the question of whether he can drive 200 winners this season, after falling short with 199 wins for the past two years.
''I tried to climb that mountain the last two years and fell just before the summit so it's something I don't need to worry about, anyway.
"If it happens, it happens. It'd be great but if it doesn't, it doesn't matter.''
With five Forbury Park meetings to go this season, it seems inevitable Dunn will set his own personal Forbury Park season best, and quickly put May's all-time tally of 240 in the shade.
He doesn't think it will be a six-win night tomorrow night at Forbury Park, but he thought Dark Side could cap off some good form in race 8.
Forbury favourites
Most wins there since 1975:
240 - Ricky May
237 - Dexter Dunn
230 - Mark Jones
161 - Clark Barron
127 - Allan Beck
123 - Ali Malcolmson
117 - Robin Swain
104 - Nathan Williamson
104 - Matthew Williamson
103 - Kirk Larsen
