The last two renewals of the St Leger at Doncaster have been incident-packed for different reasons.

The 2015 renewal will forever be remembered for the dual amendment of the result, while last year's running saw the standard-setting Idaho – sent off the 4/6 market leader – stumbling and unseating his rider three furlongs from home. His departure meant the race took far less winning and, though a close finish was served up between three horses who were separated by less than a length at the line, the form of the race, won by 22/1-chance Harbour Law, was below average for the final classic of the season from a ratings perspective.

Saturday’s race, on the other hand, is shaping up to be one of the best St Legers in recent memory, with two previous Group 1 winners set to go to post for the first time since Oaks winner Look Here went head-to-head with Irish Derby hero Frozen Fire in 2008, though that pair were ultimately left trailing in the wake of Conduit, who had previously won the Gordon Stakes at Goodwood.

Frozen Fire was trained by Aidan O’Brien and the master of Ballydoyle looks set to be represented by the latest winner of the Irish Derby here in the shape of Capri. He won the Beresford Stakes as a two-year-old, and has continued his progress this time round, including when winning the Curragh classic last time, an attacking ride and a willing attitude enabling him to turn around Epsom form with the pair that followed him home, namely Cracksman and Wings of Eagles. That form has worked out well with the second winning twice since, including the Group 2 Great Voltigeur Stakes at York, and Capri would appear to hold sound claims after two months off here, with the step up to 1¾m expected to suit.

This year’s St Leger is also similar to that of 2008 in that it features a Sir Michael Stoute-trained winner of the Gordon Stakes. The horse in question is Crystal Ocean, who is from an excellent family of middle-distance performers, including the yard's Canadian International winner Hillstar, and who identified himself as an exciting prospect when opening his account at Nottingham in April. Third in the Dante Stakes at York (Rekindling fourth) and the King Edward VII Stakes at Royal Ascot (Raheen House fourth) on his next two starts, he showed much improved form to win the Gordon (by three and a half lengths from Khalidi) six weeks ago, storming clear in the final furlong. He is unlikely to fail for lack of stamina judged on pedigree or the way he saw his race out, and should take plenty of beating.

The other Group 1 winner in the line-up is Stradivarius. He has progressed with every race this season, and made it three wins from four starts when getting off the mark at the top level in the Goodwood Cup (by one and three quarter lengths from Big Orange) last time, following up his Queen's Vase victory at Royal Ascot (by a neck from Count Octave). More battle-hardened than most in this line-up – he was the first three-year-old to win the Goodwood Cup since Lucky Moon in 1990 – Stradivarius looks a big player for the same connections that won this race with Masked Marvel in 2011, though he does still need to prove his effectiveness with give in the ground.

Defoe may not arrive here with a Group 1 success on his CV, but he has been similarly progressive in 2017, winning each of his four starts, and certainly looks worth a try in this higher grade. Indeed, he proved better than ever when winning a listed race at Hamilton (by one and a half lengths from subsequent Rose of Lancaster winner Frankuus) in July, and appeared to have plenty in hand when completing his four-timer in the Geoffrey Freer Stakes at Newbury (by three quarters of a length from Wall of Fire) last time, travelling strongly and always doing enough. The extra furlong and rain-softened ground is sure to suit Defoe here, and he looks set to go well for the Roger Varian yard that won this race with Kingston Hill in 2014.

Stradivarius’ stablemate Coronet left the impression this trip would be well within her range when five lengths second to Enable in the Yorkshire Oaks last time, and would appear to have sound place credentials, a comment that also applies to Rekindling and Venice Beach. That pair represent trainers, namely Joseph and Aidan O’Brien, who teamed up to land this race as jockey and trainer with Leading Light four years ago.

However, a place may be the best they can hope for in against some speedier rivals here and – a marginal leader from the Group 1 winning duo Capri and Stradivarius on weight-adjusted ratings – Crystal Ocean shades the vote in what promises to be a fascinating renewal.

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