Royal Ascot 2014: Aidan O’Brien can shine Light again on Gold Cup

Trainer Aidan O'Brien walks the course during Royal Ascot (PA)

Estimate brought the house down last year when becoming the first horse to win the Ascot Gold Cup for a reigning monarch since the race was first run in 1807, but those hoping for a repeat performance may be asking a bit much.

The Queen’s filly has had a far from ideal preparation this time round, a muscle problem in her right-hind leg ruling out a desired prep run.

Just as importantly, Estimate, tough and brave as she was 12 months ago, will surely need to raise her game still further to fend off last year’s St Leger winner, Leading Light (4.25 Ascot), who is showing every sign of developing into a champion stayer.

Sagaro, Le Moss and Ardross, with seven Gold Cup wins between them, were celebrity stayers in the Seventies and Eighties, while the remarkable Yeats eclipsed them all with four straight wins between 2006 and 2009.

Now Leading Light, trained, like Yeats, by Aidan O’Brien, promises to dominate for a spell and a recent decisive win over fair yardsticks Royal Diamond and Pale Mimosa on his return to action at Navan last month suggests he is ready for the quest.

Oaks form is put under the microscope in the Ribblesdale Stakes when the Epsom fourth Inchila clashes with the classy French-trained filly Vazira (3.45 Epsom).

Inchila would surely have finished second, instead of fourth, in the Oaks with a clear run and she clearly improved for the step up to a mile and a half, but the more lightly raced Vazira, clear of the rest when runner-up in a Group One contest at Longchamp last month, is roughly her equal on form and there is probably better to come.

There will be no hanging about in the Norfolk Stakes with some of the quickest two-year-olds in England (Baitha Alga and Mukhmal) and Ireland (The Great War) going hammer and tongs on ground becoming ever faster.

We can be confident the American filly To Be Determined is no slouch, either, but Mukhmal (2.30 Ascot) was hugely impressive when making all from an outside draw at Chester last month and he gets my vote.