Definition: Alternate Fairway in Golf
To be clear: We're not talking about the possibility of hitting into a different hole's fairway. This is a single hole, say the No. 5 hole on a golf course, that has two fairways.
However, it is exceedingly rare — perhaps non-existent — for a hole with alternate fairways to have two same-length fairways. When an alternate fairway is offered, it is typically much shorter than the main fairway on the hole.
So why would a golf course designer put two fairways on one hole? To provide the golfer options. The two fairways might provide the golfer with a preference of landing areas off the tee, or might provide the golfer with different angles of approach to the green, or both. The golfer would have to decide which of the two fairways on the hole best fit his eye and his game.
The alternate fairway on a hole is, as noted, typically much shorter than the main fairway. It probably either provides an option off the tee but then doesn't run all the way to the green; or provides an option on a second shot or lay-up in front of the green. In the second case, the alternate fairway wouldn't start until some point up the hole.
Alternate fairways aren't all that common, but they aren't rare, either, in golf course design. However, their use requires more land for the design of the golf course, and more water and chemicals be used in caring for the golf course. Therefore, they should become rarer over time.
Other names for alternate fairways are split fairways and double fairways.
