not to complicate things but defining a worst hole as to taken for account the context.
ex: there's nothing wrong, technically, with the donald steel holes on the Eden courseāt St. Andrews... except that they are on the Eden course at St. Andrews
About the Old Course, the worst hole out there is probably more the 6th than the 9th... not that the 6th is a bad hole, it's a good hole. But to me, the 9th is so memorable that it is really good. I've walked the course, I don't know 10 times and play it 3 times, still doesn't have a clear picture of the 6th hole.
The 9th hole has so much temptation in it... looks so easy yet. The average player has to worry about the central bunkers.. The player trying to drive the green, with some wind from the ocean, has to aim at the corner of the gorse bush 50 yards short of the green... a slight pull and it's lost ball...a terrible thought on such an easy holes so there goes the wide right miss, the indifferent pitch to 12 feet, a missed putt and there you go, a par 4 that lead a bad taste going to the 10th tee... then the player plays agressive for no reason on 10 and makes bogey...
TOC 1, the golfer 0