Zac Purton gets a first chance to turn around the fortunes of a couple of so-called “non-winners” Regency Bo Bo and Helene Charisma on Sunday at Sha Tin as the Australian looms as a chance in the Jockey Challenge.

The Tony Cruz-trained three-year-old Regency Bo Bo has finished second in five of his last eight starts while John Moore’s stayer Helene Charisma has thrown away victory after looming ominously on a couple of occasions, most notably when second to Eagle Way in the Group Three Queen Mother Memorial Cup.

The non-winner tag is usually a misnomer anyway, but for Regency Bo Bo it seems particularly unfair for a horse who won two of his first three starts and whose issues are more at the start than the finish of his races.

“Actually, Regency Bo Bo has been honest and racing well all season,” Purton said. “Maybe the handicapper caught up to him after those early wins, but he is obviously a nice horse.”

Regency Bo Bo’s tendency to bomb the start has cost the sprinter at times but last start it was a riderless horse that caused issues, not a slow getaway.

Joao Moreira had Regency Bo Bo well positioned after turning before Mr Potential caused severe interference to the gelding with 350m to go.

The other horse affected badly in the incident, Hard Ball Get, was a convincing winner last start, and should Regency Bo Bo jump on terms again, he will be difficult to beat in the Class Three Lei Yue Mun Park Handicap (1,400m).

Saturday’s rainfall and a slightly softer track should assist Helene Charisma, a French-bred import who has seemed reluctant to fully let down on firmer going.

Helene Charisma will have to lump 133-pounds in the Class Two Pok Fu Lam Country Club Handicap (1,800m).

Purton said it might be more the fact Helene Charisma is still a colt that is getting in the way of the four-year-old’s progress at this stage.

“He has a lot of ability but he isn’t the easiest horse to handle,” Purton said. “In the mornings he is fine, he is quiet, but on racedays you have to work with him, and then in a finish try and get the best out of him.

“He isn’t an easy horse by any means and that is probably why he hasn’t won a race in Hong Kong yet, but I’m going to try and turn that around.”

Sprinter Encore Boy has also developed a reputation of snatching defeat from the jaws of victory with two of his four starts narrow seconds after looking the winner late.

Purton didn’t have many excuses other than inexperience for Encore Boy after the Ricky Yiu Poon-fai-trained sprinter was nabbed on the line by Lunar Zephyr last start.

Now the gelding returns to the same 1,000m course he has contested at each of his four starts in the Class Four Lei Yue Mun Public Riding School Handicap (1,000m).

“He has looked like he has had two races in the bag and for whatever reason in the last 50 metres he has just fallen in a hole,” he said. “So at the moment he isn’t ready to go beyond 1,000m, but if he can get a nice enough run in transit he is going to be right in the finish again.”