The team at Lindsay Park is preferring to look at weights rather than barriers when assessing the prospects of Mr Brightside in Saturday’s $3 million Doncaster Mile at Randwick.

The four-year-old was on Tuesday allocated barrier 21 for the 1600-metre Group 1, which will become 18 in the field of 20 if the emergencies don’t gain a start.

But he gelding still meets second favourite I’m Thunderstruck significantly better at the weights for their All-Star Mile meeting, when Mr Brightside finished fourth and I’m Thunderstruck second, with Ben Hayes suggesting he needs only to run up to that form to be a chance.

I’m Thunderstruck was beaten 1-1/4 lengths by Zaaki in the All-Star Mile with Mr Brightside a 3-1/2-length fourth.

They both carried 59kg in that event with Mr Brightside dropping to 50kg on Saturday, while I’m Thunderstruck has 55.5kg.

“We’re getting 5.5 kilos off him and he’s one of the main dangers, so with that weight turnaround he could turn the tide,” Hayes, who trains in partnership with brother JD, said.

“With the big weight drop and considering how well he ran in the All-Star Mile after missing the start, he has to have a good each way chance.”

Mr Brightside is a $21 chance in TAB’s Doncaster Mile market, which is headed by Forbidden Love at $4.50. I’m Thunderstruck is a $5 chance.

The unknown for Hayes is the almost-certain Heavy track and while untested on that surface, the Kiwi-bred son of Bullbars has won four of six on Soft ground including his only three runs on Soft 7 tracks.

“With the Heavy 10, I’m not sure how he’ll handle it, but he’s won of a Soft 7,” Hayes said.

“His work out of the All-Star Mile has been fantastic. We can’t fault the horse one bit; he’s fourth up, rock hard fit and this is his Grand Final.”

Mr Brightside will be ridden by Craig Williams, who is chasing his first win in the Doncaster Mile.