It's apt that the Cheltenham Festival always falls around the same time as the national holiday, because there is an argument that horse racing - especially of the jumps kind - is Ireland's true national sport, writes Frank McNally.
Yes, its actual national championships don't happen until April, and are held in Kildare rather than Gloucestershire. But the importance of Cheltenham is that it combines a quintessentially Irish sport with a national obsession: stuffing it to the English, preferably on their own turf. Sadly, this is not an option offered by hurling.
There are those who consider even flat racing's poor relation as a sport for toffs, and they have a case too. Although breeding is not nearly as selective in National Hunt racing - among either the horses or the people who own them - the very name betrays its origins in the gentry's pursuit of foxes.
The sport certainly has some vestiges of the old aristocracy - Yeats's "hard-riding country gentlemen" - not least in that, outside the Orange Order, it is Ireland's last bastion of hat-wearing by men.
Unless you're the kind of person who bleeds green, memory of the Penal Laws - when the native Irish were not allowed to own a horse worth more than £5 - should have faded by now. But especially in the northern half of the country, where the Penal Laws met Puritanism, there are still large swathes of land where sports horses are shunned. Hurling is scarce there too, funnily enough.
Jumps racing remains strongest where it began: in the south. Europe's first recorded "steeple-chase" happened more than 250 years ago, between the churches of Buttevant and Doneraile in Cork: a four-and-a-half-mile trip still echoed in the greatest steeplechase of all, at Aintree.
But at this time of year, the Irish interest in racing is more or less nationwide. Even if you are not one of the thousands who breed, own, train, ride, or muck out after horses, you are probably vulnerable to the mania that turns the most rational Irish people into gamblers when the word Cheltenham is mentioned. In mid-March, rumours of good things circulate like respiratory viruses, and infection is hard to avoid.
Even at a time when the European lottery is displacing the local version because a million euro no longer seems a big enough prize, the idea of taking a few quid off the bookmakers has not lost its charm. This is because the attraction goes well beyond money. To be part of a successful gamble means that you were in the know, which is a place Irish people love to be.
The losers are less likely to talk, of course. But half the fun of winning is that you can brag about it. One of the drawbacks of covering Cheltenham and visiting the winner's enclosure regularly is the constant exposure to people who knew for months that their horse was a certainty and backed him at 40, or 50, or 66 to 1.
As for breeding, one of jump racing's big advantages is that most of its runners are incapable of it. Male National Hunt horses are usually gelded - which, among other reasons, means that their racing careers are much longer than those of their counterparts on the flat.
The tyranny of the thoroughbred breeding industry was dramatically illustrated at the weekend when one of Aidan O'Brien's best three-year-olds was sacrificed to a career at stud, after his older relative proved infertile and left Coolmore with a huge gap in the books. On Saturday morning, Holy Roman Emperor was still favourite for the 2,000 Guineas. By evening, he was retired and already making babies.
Jump horses may never know the joys of parenthood, but the consolation is that - barring physical misfortune - they run for long enough to become characters, often much-loved. Some are flawed heroes; some are villains with redemptive qualities. All have story lines you can get involved with.
For example, hardened punters have long given up on Beef or Salmon - a horse that, like Guinness, appears not to travel well outside Ireland. But it would be a hard-hearted person who won't cheer if he finally overcomes his aversion to foreign holidays this week and wins the Gold Cup.
We can even identify with jump jockeys more easily than their miniature cousins. Flat jockeys are like fashion models: waif-life creatures whose physiques you can't help worrying about. Jump jockeys are not exactly curvy either, and many are also martyrs to the weight-loss programme. But if you're Ruby Walsh or Mick Fitzgerald, you can look like a normal human being and still be among the best at the job. Most of the best jump jockeys are Irish, in fact, and they are the bravest sports stars we have, constantly risking serious injury and worse, for far less money than they deserve.
It's a minority interest, I admit. But for me, an important part of the entertainment at Cheltenham is the dramatic tension between the race-caller and horses named in Irish. In this respect, the big hope for 2007 is Cáilín Álainn, which threatens to do for an English commentator what Cheltenham's fences do for dodgy jumpers. Then again, the money last year was on a horse called O'Muircheartaigh, and the commentator was foot-perfect.
This may be a sign of the times. That the English are finally learning to handle Irish pronunciations is a compliment to the shift in horse-racing's power balance in recent years. An injury jinx this year means it will be hard to repeat last year's feat, when the Irish raiders cleaned up. But it's a fair bet that, come Friday, Irish trainers will again be the biggest winners, after the bookies.