If asked, in mid-August, to name the colt likely to end up champion two-year-old, many shortlists would have included Expert Eye, Unfortunately, or Sioux Nation. We're almost at that point now, but the one who may top the rankings would surely not have been on anyone's list.
By that time, U S Navy Flag had run seven times, beaten in his first four starts, then a Curragh maiden winner in first-time blinkers before chasing home Cardsharp in the Group 2 Arqana July Stakes at Newmarket and then taking fourth to Sioux Nation, Beckford, and Actress in the Group 1 Keeneland Phoenix Stakes.
Since then, however, the Aidan O'Brien-trained son of War Front (by Danzig) has run three times and won all three, and he is due to round off his year with a try on dirt in tomorrow's Grade 1 Sentient Jet Breeders' Cup Juvenile over a eight and a half furlongs at Del Mar.
Just a fortnight after his Phoenix Stakes run, he put up a surprisingly good performance to win the Group 3 Plusvital Round Tower Stakes by six lengths from Landshark, on ground described as yielding. It is fair to say that it was not a particularly strong race for the grade, but he could hardly have been more impressive.
Even so, he was not the stable's first string in the following month's Group 1 Juddmonte Middle Park Stakes. But Sioux Nation disappointed in sixth there, just ahead of another Ballydoyle runner, Declarationofpeace, while U S Navy Flag stayed on well to beat the other Aidan O'Brien-trained runner Fleet Review by half a length.
It gave the trainer and the sire a one-two in England's top juvenile six-furlong contest, and the pair finished two and a quarter lengths clear of the third, Cardsharp.
This was still not enough to put the colt at the top of the rankings, but then he beat his stable companions Mendelssohn, Seahenge and Threeandfourpence – by two and a half lengths, two and a half lengths, and a head – in the Group 1 Darley Dewhurst Stakes at Newmarket, with old rival Cardsharp another length and a half back in fifth.
Timeform raised his rating to 123, the highest figure awarded to any juvenile this year. The runner-up advertised the form with victory in tonight's Grade 1 Breeders' Cup Juvenile Turf over a mile at Del Mar, and both colts look like leading classic contenders for 2018.
With 10 races already behind him – and his 11th start of the year due tomorrow – there may not be much improvement still to come from U S Navy Flag, but that does not mean that he cannot win a Guineas.
If, however, you look at the amount of improvement he has made since mid-August, factor in that his best performance came when stepping up to seven furlongs and that, on pedigree, he's bred to be a miler who could stay 10 furlongs, then there is a chance that we have not yet seen the best that he can do.
Regardless of how he fares as a three-year-old, however, U S Navy Flag will likely be a popular addition to the Coolmore stallion team whenever his racing days come to an end and not just because he's a multiple top-level juvenile winner by Claiborne Farm's excellent sire War Front (by Danzig).
For starters, he is the third foal of Coolmore's top-class runner Misty For Me (by Galileo), the Group 1 Moyglare Stud Stakes, Group 1 Prix Marcel Boussac and Group 1 Irish 1000 Guineas heroine who trounced Midday by six lengths in the Group 1 Pretty Polly Stakes over 10 furlongs at the Curragh, and he was bred by the syndicate that bears her name.
That makes him a half-brother to the US mile Grade 3 winner Cover Song (by Fastnet Rock) and a full-brother to his Timeform 120-rated fellow Ballydoyle resident Roly Poly, whose most recent of three Group 1 wins came in last month's Kingdom of Bahrain Sun Chariot Stakes, in which she beat subsequent Group 1 Queen Elizabeth II Stakes heroine Persuasive by a length and a quarter.
She ran eight times at two – winning the Group 3 Grangecon Stakes and Group 2 Duchess of Cambridge Stakes and being short-headed by Brave Anna in the Group 1 Cheveley Park Stakes – and when she lines up for tomorrow night's Grade 1 Breeders' Cup Mile at Del Mar, it will be for her ninth start of the year.
In addition to the aforementioned Newmarket feature, her Group 1 wins have come in the Falmouth Stakes on the July Course at Newmarket, in which she beat Wuheida by one and a quarter lengths, and in the Prix Rothschild at Deauville, where she beat the sadly ill-fated Via Ravenna by a short-neck.
She has been unplaced three times this year, but chased home Timeform 124-rated grey Winter – another Aidan O'Brien trainee – in both the Group 1 Irish 1000 Guineas and Group 1 Coronation Stakes.
Just these credentials would be more than enough to make the case that U S Navy Flag could be a high-class miler or 10-furlong horse in the making, but these star relations are just the tip of the iceberg, so to speak.
Misty For Me is a full-sister to the Group 1 Prix Marcel Boussac winner Ballydoyle, who chased home Minding in both the Group 1 1000 Guineas and Group 1 Irish 1000 Guineas last year, and she is out of Butterfly Cove (by Storm Cat), who is an unraced half-sister to the unbeaten juvenile Group 1 sprint star Fasliyev (by Nureyev).
He compiled a respectable record at stud, getting stakes and pattern winners among a long list of successful runners, and the same can be said of his dam's half-brothers Desert Wine (by Damascus) and Menifee (by Harlan).
How U S Navy Flag performs in tomorrow's Grade 1 Breeders' Cup Juvenile may give us a hint as to the future direction of his racing career. If he handles the dirt and can make the frame then perhaps a Grade 1 Kentucky Derby bid might be on the cards, rather than the Group 1 2000 Guineas at Newmarket.