By the time Rory McIlroy finished his first practice round for the British Open at Royal Portrush, a big crowd that weathered rain and sunshine was waiting to see him finish.

HOLYWOOD, Northern Ireland — Two decades before Rory McIlroy’s career-defining triumph, when he finally conquered his Masters demons with an emotional rollercoaster of a win at Augusta National, he did, in fact, already own a green jacket.