Just as Victoria has the Spring Carnival culminating in the Melbourne Cup, Australia's flat horse racing calendar soon moves on and shifts focus to the state of Western Australia.

Three very valuable races help to form the Perth Summer Carnival across consecutive weekends in November and December at Ascot racecourse. Not to be confused with the English equivalent that hosts both flat and jumps action, this Ascot Down Under is just a few kilometres east of Perth city centre opposite the headquarters of the Western Australia Turf Club, better known as Perth Racing.

The second of those valuable prizes run at Ascot during their Summer Carnival is the Group 1 weight for age Winterbottom Stakes over 1200m (about six furlongs). Prior to the launch of The Everest in 2017 at Randwick, it was one of the most valuable sprint contests in all of Australia.

It remains an attractive pot and has history, which that new race in Sydney lacks, however, so the Winterbottom always attracts a good turnout both in the quality of horses and crowd numbers. This year's renewal should be no exception.

Which horses are considered leading Winterbottom Contenders and why? Let's take a detailed look at four...

Viddora

An obvious place to start is with last year's winner Viddora. The six-year-old mare shaped really well in a couple of starts at Moonee Valley en route to her triumph in this 12 months ago when a short-head second in the Cramer Moir Stakes giving away 15lb to She Will Reign.

Viddora vastly outran massive odds of 30/1 and was then a two-length fourth in the Manikato Stakes. This put her spot on for a crack at the Winterbottom and she landed the spoils under regular jockey Joe Bowditch for trainer Lloyd Kennelwell, scoring by 1 1/2 lengths.

Only three horses have won back-to-back renewals of this race since it was inaugurated in 1952 - La Trice (1970 and 1971), Belinda's Star (1975 and 1976) and Hardrada (2002 and 2003). While that means this is a big ask, Viddora has come out and recorded more Group 1 success this season.

After winning a barrier trial on reappearance, she clearly came on for that when going one better in the Cramer Moir in September and scoring by a cosy length. Connections were entirely justified in their decision to go for The Everest off the back of this effort, but the heavy going Viddora encountered at Randwick just didn't suit her at all.

Brave Smash, the Cramer Moir, runner-up finished two places in front of her in Sydney, but she then took a step back in the right direction by winning another barrier trial at Cranbourne last month. If lining up to defend her crown at Ascot, then Viddora sets an obvious standard and is entitled to be a strong favourite in the 2018 Winterbottom Stakes betting as compiled by Oddschecker.

Enticing Star

While Viddora is one of many raiders from Eastern Australia with a prominent place in the market, five-year-old mare Enticing Star heads the locally trained potential runners. While she comes into the Winterbottom off the back of a first stakes defeat in the Group 2 Lee Steere, she is thought to have been in season and prior to that had a progressive profile.

Although the calibre of races won by Enticing Star doesn't match the class and clear standard set by Viddora, she is two out of three at the course and four from four at the 1200m trip. That makes dropping back down in distance an obvious plus.

This daughter of Testa Rossa is trained by Adam Durrant and regularly partnered by William Pike. Since coming a disappointing sixth in the Lee Steere, Enticing Star has since won a barrier trial and still comes into the Winterbottom as a respected rival and perhaps even the main danger to the favourite.

Malaguerra

Seven-year-old gelding Malaguerra placed in front of Viddora when third in the 2017 running of the Manikato, so if turning up in the same shape as that is not without a chance. The Peter Gelagotis trained son of Magnus has a very respectable 12 wins from 30 career starts and he's got two Group victories on his resume like the market leader.

Malaguerra was beaten just a length into fifth in the Winterbottom two years ago in a blanket finish behind Takedown. On the pick of his form in sprint contests that are often decided by the finest of margins, he thus cannot be entirely ruled out.

The only concerns if you're thinking of backing Malaguerra would be his age and whether he can recapture past form. His return to action in the Manikato saw him down in 12th place, but like the other market principals, he has landed a barrier trial since.

Voodoo Lad

Darren Weir of one of Australia's training heavyweights and is represented in the Winterbottom this year by Voodoo Lad. This seven-year-old shares a sire with Vidorra in I Am Invincible.

While he's never scored at higher than Group 3 level, that does not tell the whole story with Voodoo Lad as he's also run some solid races in elite company. Those include when a 4 3/4 lengths 10th - and in front of Viddora - in the Group 1 Darley Goodwood at Morphettville back in May.

He was also a 3 1/2 lengths eighth in the Manikato when ahead of Malaguerra, yet unlike the other leading contenders according to the Winterbottom Stakes betting, Voodoo Lad goes to Ascot without a barrier trial under his belt.

Weir does things differently. He's only put Voodoo Lad in one such race the whole time the horse has been in his yard. This confidence that he can get the gelding fit at home is reassuring.

On all known form though, Voodoo Lad is probably a little bit out of his depth in Group 1 races, though this is unlikely to be as fiercely competitive as some of the events he's run in. Bearing that in mind, he could be the value each-way bet on the Winterbottom Stakes.