A sickening bias at Happy Valley on Wednesday night made black bookers difficult to find and the form will mostly be unreliable but one or two performed with credit against the disadvantage and punters could get a very quick return from one of them on Sunday.

Almost every winner on Wednesday was in front or within half a length of the lead straightening for home, regardless of pace. Few horses made much impression from off the pace in the final 300m, and those who did mostly came along the better rail section.

The John Size-trained Ensuring backs up in the Class Two over 2,000m after resuming from seven months away behind Unicorn and he was finding the line very well out in the centre of the track to finish fourth.

Size had given Ensuring a tremendous foundation, with seven barrier trials and the six-year-old didn’t appear to have missed training since October.

Ricky Yiu’s Packing Dragon prevails to collect Happy Valley Million Challenge

Given that the plan was always to back him up into Sunday’s race, there should be no concerns about Ensuring lacking fitness or suffering a bounce effect.

The gelding hasn’t won since July 2015, but last season had decent form around the likes of Supreme Profit, Top Act, Anticipation – similar styles of horse to what he meets this weekend and he should be competitive.

Another who did a good job against the bias was Amazing Feeling in the fourth race. With the Richard Gibson yard out of form, it just hasn’t been happening for Amazing Feeling, but his running on third was positive.

Now, he did have the benefit of running on in the better part of the track nearer the inside, but Amazing Feeling gets some extra credits because he might well have won the race but for being held up on the circle when jockey Umberto Rispoli would have liked to improve into the race to be in closer range at the 300m.

It is remarkable that Amazing Feeling is still a maiden after showing so much promise as a three-year-old and he has placed at more than 50 per cent of his races but this was an indication he might soon add a win to that record.