Once more it's that time of year – the first Saturday in June – and thus time for the running of the Investec Derby at Epsom, southwest of London. The "Blue Riband of the Turf" is programmed to go off at 4:30 p.m. BST (9:00 p.m. in India) on Saturday, June 4^th, and the event bears a very open look.

Whether this is due to the actual lack of a "standout" three-year-old colt in the 2013 crop, or whether there is a top-class individual in the field which has not as yet revealed the full extent of its ability, will be known in the fullness of time. At any rate, as many as 16 – which include 4 supplementary entries – have been declared, all in chase of fame and glory, not to mention a share of the £1,545,000 prize money. This will be the richest race ever run in Great Britain.

Following some rain during the week, the official description of the ground conditions at Epsom as on Thursday has been recorded as "Good to Soft, Soft in places"; with isolated showers in the forecast, which could materialize on Friday and Saturday, the going could change. As English weather is famed for its unpredictability, one would need to check the position closer to the "off". Should it pour, the result of the race could be materially affected. Most likely, though, it will be cloudy and around 20 degrees Celsius.

Irish trainers have supplied exactly half the winners of the last 16 renewals of the Epsom Derby, this rich vein of success coming after a lean period for that tribe, when only a solitary runner (Secreto) kept the Emerald Isle on the top of the board in the previous 16 years.

As many as 7 of this year's participants hail from across the Irish Sea, while just a solitary runner from France will be following the dictum "Go West, young man" and has accordingly booked its ticket across the Channel. Ireland's ace trainer, Aidan O'Brien, ran up a hat trick in the Derby through Camelot (2012), Ruler Of The World (2013) and Australia (2014), but missed out last year as his ammunition was inadequate. In an effort to make Ballydoyle the default destination of the Derby trophy, O'Brien has pitched in no less than five runners on this occasion, headed by the much-vaunted US Army Ranger (by Galileo), who is the shortest priced of the quintet at 5 to 1.

Noticeably weak in the betting market despite the presence in the saddle of Ryan Moore, whose previous wins in the Derby came through Workforce (2010) and Ruler Of The World three years later, US Army Ranger is unbeaten from 2 starts. He is touted to be that much-awaited "star", but his level of form is such that he would need to show significant improvement even to account for his stablemates, leave alone the opposition. Of course, this uptick in performance is entirely possible for one of his provenance.

Port Douglas (by Galileo) just knuckled under to US Army Ranger in the Chester Vase last month, but as he was conceding 4 pounds to his barnmate, the former comes out slightly on top on the ratings. Colm O'Donoghue has been pencilled in for the ride and while he has scored in the Irish version (through Treasure Beach) and the Indian equivalent (with Diabolical), he has yet to oblige in "The Derby". His mount is on offer at 20 to 1 against.

Significant money has poured in recently on the O'Brien-trained Deauville (by Galileo), bringing his price down to 8 to 1 before it rebounded to 9 to 1. The bay sports the racing silks of part-owner Mrs. Fitri Hay, with the Coolmore partners owning the remaining part of this engaging colt. Runner-up in the Betfred Dante Stakes – a recognized Derby trial, won last year by Golden Horn en route to his Epsom triumph – Deauville will be steered by Mrs. Hay's retained rider Jamie Spencer, who rode a couple of winners in India during a short stint in the subcontinent in January 2013. Given that the Dante was his first appearance since last year, Deauville can be expected to show improved form – but will that be enough?

Seamie Heffernan's mount, Idaho (by Galileo), at 12 to 1, will join Shogun (by Fastnet Rock), to be ridden by the trainer's son and quoted at 66 to 1, as the remaining runners from County Tipperary. No, the trainer's son in question is not Joseph, who has retired from the saddle due to increasing weight problems, but the latter's younger brother, Donnacha, who will be making his Epsom Derby debut as a teenager. Incidentally, there is some quiet confidence behind Idaho, a full-brother to the globe-trotting Highland Reel – it's felt he is peaking nicely at this time and his price has contracted from sixteens. He was placed in a couple of the recognized Derby trials this Spring and won't need to improve too much to have a say in the finish.

Last year's winning formula in the Derby was an improving three-year-old, schooled by John Gosden, supplemented to the race, seasoned by valuable experience in the "Dante", and guided in inimitable fashion at Epsom by the exuberant Italian ace, Frankie Dettori. Could Wings Of Desire (by Pivotal) be a replica of Golden Horn? He certainly won the Dante in the manner of a good horse and just to spite those who would aver that a son of Pivotal will not stay 12 furlongs, Wings Of Desire has already won over the trip!

Despite a fall on Tuesday, Dettori was upbeat, saying: "I slipped after the line at Leicester on Tuesday but despite a few bumps and bruises I'm raring to go for Epsom…..I'm not going to let a fall derail my bid for more Classic glory. I've got a good favourite's chance in the Derby and the forecast rain doesn't do us any harm." Lady Bamford's homebred is a lukewarm favourite at 9 to 2 and time might show that lightning does indeed strike twice….

The Godolphin silks have never led home the Derby procession at the wire. Last year, the distinctive blue colours had to settle for second astride Jack Hobbs, a respectable 3½ lengths in arrears behind Golden Horn. There is a very real chance that this year Sheikh Mohammed's dream will come true, as his veteran French trainer is sending over Cloth Of Stars (by Sea The Stars) who comes to Epsom as a live chance. A supplementary entry, he has experience (6 starts), consistency (4 wins and 2 places), adaptability (winner on rain-affected ground and going left-handed) and an association with a Derby-winning team (Andre Fabre and Mickael Barzalona) – they scored in 2011 with Pour Moi. The 400,000 guineas yearling will be worth many multiples of his purchase price should he land the 7 to 1 odds.

According to the well-respected trade publication, the Racing Post, the highest-rated runner in the field is the 2000 Guineas runner-up, Massaat (by Teofilo), whose dam is a half-sister to Pratap Stud's Deserting, and whose third dam, Gourgandine, spend 16 productive years at the Usha Stud. Sheikh Hamdan's 14 to 1 hope will be ridden as usual by Paul Hanagan. As the homebred has never been out of one-two, he could be one who is flying under the radar as far as public estimation is concerned, though there are legitimate queries about his stamina.

H.H. The Aga Khan has had the pleasure of breeding no less than four Epsom Derby winners, all sired by stallions not owned by him. It's been a long while – 16 years – since he last led in the winner of the race and no doubt he will be hoping that his latest candidate, Harzand (by Sea The Stars) obliges. Dermot Weld's charge is in fine form, having been patiently brought along to win both his starts this term – on heavy going. Usual rider Pat Smullen will partner the brown colt, available at 14 to 1.

If anyone can wring out drastic improvement in a very short time, it is Sir Michael Stoute, who has five Derby scalps to his credit. In the Niarchos homebred Ulysses (Galileo – Light Shift), he has a blue-blooded youngster who, like Australia, is by an Epsom Derby winner out of an Epsom Oaks winner and thus bred for the job. However Ulysses has yet to run in, leave alone win, a stakes race and the runaway maiden winner looks the sort to do better with time. The services of Andrea Atzeni have been secured for the 7 to 1 chance. 

Sir Michael also saddles Across The Stars (by Sea The Stars), a 33 to 1 outsider in the capable hands of Kieren Fallon. It may be recalled that this very combination annexed a pair of Derbies through Kris Kin and North Light.

No grey horse has won the Derby since Airborne (1946) became the most recent of just 4 of that hue to triumph in the world's premier classic. Hoping to rectify the balance is David Simcock's Algometer (by Archipenko), with regular pilot Jim Crowley at the controls. Winner over 11 furlongs, the homebred grey ought to stay the trip and is one of a handful of lightly-raced hopefuls that could step up in form. Should that occur, a potential wagering investment would be multiplied sixteen-fold.

The extraordinary dominance shown by the German-bred broodmare, Allegretta, can be inferred from the fact that no less than 12 of the 16 runners in this year's field have her blood coursing through their veins! However, her only direct descendant in the female line is Godolphin's second string, Moonlight Magic (by Cape Cross), who boasts a real stallion's pedigree. The pupil of the Bolger/Manning combine has 3 wins from 4 starts, and thus seems decent value for the 10 to 1 odds on offer.

It would be remiss not to mention two of the four supplementary entries. Red Verdon (by Lemon Drop Kid) is a rare American-bred participant, who has hitherto shone only in handicaps and is making a big class jump. Silvestre De Sousa assumes command on Ed Dunlop's 20 to 1 shot. Despite his short-running sire, Humphrey Bogart (by Tagula) will probably stay the trip, having winning form at just half a furlong less. His last seven starts have been under the direction of Sean Levey and there is no change on Richard Hannon's ward, whose 33 to 1 quote is reflective of his chances.

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 riddle which admits of no easy answers! Will it rain? All one can do is to whittle down the contenders to "possible". Even that would produce too long a list. So we will go in for nothing more assured than mere hunches. The following names represent my shots in the dark: Cloth Of Stars, Idaho, Massaat and Moonlight Magic.