Secondly, he looks one of the better handicapped runners on show having been allotted an official mark of 97 when the weights were published last month.
And last but not least, Persian Lightning is just the sort of quietly progressive horse you look for when trying to solve major handicaps.
First time out this season he pulled too hard for his own good at Pontefract, but Eddery was alive to the situation at Newmarket on 2,000 Guineas day and allowed him to stride on for a ready victory.
Persian Lightning's headstrong tendencies surfaced again when he finished an honourable fourth behind Hazim in Redcar's Zetland Gold Cup, but at Royal Ascot he settled beautifully and ran the race of his life to chase home In Time's Eye in the Wolferton Rated Stakes.
The winner landed one of the gambles of the season that day, while the third seemed to be improving fast and the fourth horse Samhari has run another fine race since.
What's more, Persian Lightning ran even better than the bare result suggests at Ascot, as he was left with more to do than ideal once the pace quickened swinging for home and quickened impressively to get within a neck of the winner.
Trouble in running and the draw can always play a part in big fields at York, but Persian Lightning has the early speed to take up a good position. Fast ground and 10 furlongs on fast ground looks perfect for him and, with Eddery as hungry as ever, everything looks in place for a very bold effort.
Sunday's main action centres on the Curragh, where Yesterday will bid to take her revenge on Casual Look in the Darley Irish Oaks.
Michael Kinane was in the firing line after Yesterday found trouble aplenty when going down by a neck to Casual Look the Vodafone Oaks at Epsom.
In truth he was most unlucky, as a series of gaps closed on him in the straight, but Yesterday galloped on relentlessly once in the clear.
Casual Look never runs a bad race, while Spanish Sun got the better of a cracking finish with Ocean Silk in the Ribblesdale Stakes at Royal Ascot and is clearly on the up.
However, Yesterday looks to have the edge. The stiff Curragh track should suit her ideally and, no matter what recent evidence might suggest, no trainer beats Aidan O'Brien when it comes to getting a Classic contender to peak on the big day.
Weekend big-race selections -
York (tomorrow): 3.05, Persian Lightning; The Curragh (Sunday): 4.15, Yesterday.
FRANKIE DETTORI has been booked to ride the Paddy Mullins-trained Vintage Tipple in Sunday's Irish Oaks. Betting for the Curragh race (Paddy Power): 13-8 Yesterday, 7-2 Casual Look, 9-2 Ocean Silk, Spanish Sun, 8 Hanami, 12 bar.
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