Royal Troon applies a handicap threshold of 20 for gentlemen, and 30 for ladies
Prestwick applies a handicap threshold of 24 for gentlemen, and 28 for ladies respectively.
Some known issues to consider
Royal Troon doesn't operate a visitors shoulder season
A day-trip to play on the Isle of Arran might be disrupted by a ferry failing sail. In truth, if the weather has stopped a ferry, it's probably stopped golf anyway. We can usually manage around this however as we simply stay on the mainland and play elsewhere
If you don't wish to take the hopper flight to Machrihanish, the alternative road trip around the Kintyre peninsula takes about 4 hours
Dundonald does periodically host the Scottish Open which will close it down from mid June until early/mid July