Ah, The Derby! That prototype for excellence in Classic flat racing! The model for copycat events round the globe! One could go on and on regarding the importance of the Investec-sponsored race, whose 236^th renewal is due to take place on Saturday, June 6^th at 4:30 p.m. BST (9:00 p.m. in India) at Epsom Downs, Surrey, with a dozen three-year-olds colts engaged.

Was it not legendary Italian breeder Federico Tesio, who proffered these words of wisdom: "The Thoroughbred exists because its selection has depended, not on experts, technicians, or zoologists, but on a piece of wood: the winning post of the Epsom Derby. If you base your criteria on anything else, you will get something else, not the Thoroughbred"? Given that Tesio gifted the world such masterpieces as the unbeaten Ribot and Nearco, whose blood courses through the veins of a majority of racehorses these days, the significance of winning the Epsom Derby is self-evident.

The ground conditions at Epsom are expected to range from "good" to "soft",  depending on how much of the forecast rain materializes on Friday. The localized thunderstorms in the area are expected to clear away by the same night and the day of the race should be dry and warmer, ideal conditions really for both the equines and the humans who are expected to turn up in droves.

As Irish-trained horses have won eight of the last 15 runnings of the Epsom Derby, after a complete drought in the 15 years preceding, racing fans have looked to the Emerald Isle for the likely source of the winner. In fact, all spring long talk has centred on whether Ireland's ace trainer, Aidan O'Brien, can extend his string of victories in the race, having scaled the "Mount Everest" of racing the last three years through Camelot (2012), Ruler Of The World (2013) and Australia (2014). However, many of his hopes have since fallen by the wayside and as a result even his best-fancied runner is now at 7 to 1. We will get to them in due course.

Many people's idea of the winner is the supplemented (at a cost of £75,000) Golden Horn (by Cape Cross), the favourite at 6 to 4. John Gosden's ward is to be guided by the irrepressible Frankie Dettori, who missed out on rides during each of the last three years in what tradition holds to be the world's most famous race. Although the colt's sire gained honours in this event by siring Sea The Stars (2009), a glance at Golden Horn's pedigree reveals ample reasons to justify his owner's original decision not to nominate him at the initial entry stage. The bottom line is full of speedy, short-running names.

That said, his racetrack performance has been somewhat different. Unbeaten in three lifetime starts, he has this year won the 9 furlongs Fielden Stakes at Newmarket and the 10 furlongs Dante Stakes at York in the manner of a stayer. And uncommon is the winner of these races which does not last out the 12 furlongs Derby trip, although a ready example of one whose stamina proved insufficient comes to mind in Alnasr Alwasheek! Golden Horn would also not like soft conditions, should they come into play.

Although confident in the ability of his mount, Dettori – who won the Derby in 2007 with Authorized – admits to healthy respect for stablemate Jack Hobbs (by Halling), on whom the Italian ace was outpointed in the Dante at York by the sustained late run of Golden Horn. "I am frightened of Jack Hobbs," said Dettori. “I still think he is a good horse. My horse is favourite, he won his trial well and of course I am excited to be riding him. We will see what happens on Saturday.”

Named after the illustrious cricketer Sir John Berry "Jack" Hobbs, Gosden's second string, now part-owned by Godolphin, is to be partnered by William Buick. The thrice-raced colt has an excellent record consisting of two facile victories before finishing as the runner-up last time out, nailed by the late run of Golden Horn. Being out of a Swain mare from a stout family – his fourth dam's half-brother Connaught nearly won the 1968 Derby – Jack Hobbs has the advantage of being sure to stay. He is generally available at 9 to 2 and is a live prospect. However, his trainer intends to walk the course on raceday morning to determine whether it is not too "quick" to risk him.

The increasingly-prominent Qatar Racing Ltd. fields a pair. One of the outfit's runners is a 100 to 1 forlorn outsider, but the 7 to 1 Elm Park (by Phoenix Reach) can be said to hold a realistic chance. Never unplaced, the experienced bay will prefer some "juice" in the ground, so is one to watch if the going is softer than good. Andrea Atzeni will get an opportunity to vie for Derby honours astride Andrew Balding's charge, who has six lengths to make up on Golden Horn on the Dante Stakes form. That was Elm Park's seasonal reappearance and he may be expected to improve.

Those who read this column last week would have noticed the comment on Juddmonte runners in classics needing to be respected – an opinion that bore fruit when New Bay essayed a brilliant victorious run. Readers would also have noted mention of that operation's other leading three-year-old, the high-strung Epicuris (by Rail Link), and his travails at the start. Having been intensively schooled since then, the bay will hopefully accord consent to efforts to make him enter the gates here as the sole French challenger.

Unbeaten as a juvenile, he lost to Silverware in his lung-opener this spring, but as that runner ran poorly last week in the Prix du Jockey Club-French Derby one has to be concerned about the level of the form. Trainer Criquette Head-Maarek will be saddling only her second Epsom Derby starter in Epicuris, after American Post sported the same silks when unplaced in 2004, and saddle duties have once again been assigned to the colt's regular rider, Thierry Thulliez. The package is on offer at 16 to 1.

Coming now to the Irish challenge, a significant move was the supplementation of P.W. McGrath Memorial Ballysax Stakes and Derrinstown Stud Derby Trial winner, Success Days (by Jeremy) into the race. Justifying his decision, Co. Kildare-based trainer Ken Condon said: "He's won the best two trials in Ireland and he certainly deserves his place in the line-up. People can say he's been winning in small fields and on bad ground but the ground is always soft in Ireland in the spring." Shane Foley will ride the 16 to 1 chance, who is frankly speaking not bred to win a Derby.

Coolmore will send out three participants for the "Blue Riband of the Turf". Two of them – Kilimanjaro (by High Chaparral) and Hans Holbein (by Montjeu) – have annexed major Derby trials in England (the team's candidates in the corresponding races in Ireland were all beaten and so are mostly absent). The grey Kilimanjaro won the Chester Vase under Ryan Moore, but now has Joseph O'Brien donning silks and is at 16 to 1, while the 14 to 1 Hans Holbein (by Montjeu), with Seamie Heffernan up, provides one last opportunity for his illustrious sire to notch up an historic fifth win in the Derby. The late Montjeu's previous winners were Motivator (2005), Authorized (2007), Pour Moi (2011) and Camelot (2012).

That brings us to Giovanni Canaletto (by Galileo). As an own-brother to Epsom Derby winner Ruler Of The World and half-brother to King George VI & Queen Elizabeth Stakes hero Duke Of Marmalade, he clearly has outstanding pedigree credentials to win the Derby. Ballydoyle's 7 to 1 chance has gained the nod from Ryan Moore, arguably the leading rider in the world, despite his narrow loss to a handicapper just 13 days ago in the Airlie Stud Gallinule Stakes. "Giovanni Canaletto seems in good form…...It isn't ideal running him back so soon, but he finished well in the Gallinule and Ryan liked him", said his trainer. Lightly-raced, the colt could well progress and pull it off.

What would have been perhaps the leading Irish challenger, veteran Dermot Weld's Zawraq (by Shamardal), suffered a recent scare when a leg filled up slightly leading to lameness. Thus he has been a late scratch. 

Weighing up the alternatives, it looks like there is something to like or dislike about each of the leading contenders, and at this stage at least it's veritably a puzzle! Will it rain? Will Golden Horn stay? Are the others talented enough? It takes a really good horse to win this prize and one feels that only Elm Park, Epicuris, Giovanni Canaletto, Golden Horn, Hans Holbein and Jack Hobbs have laid enough of a foundation towards the honour of being considered in the league of a "Derby winner".