Like many golf courses, Canal Shores had seen fewer rounds played in recent years. The century-old course north of Chicago was projecting another downturn this year when, in the spring, its management group began to think about how it could reverse the trend.

On a map, the par-60 course is laid out like most others in the U.S., an 18-hole route that takes players away from the clubhouse and back. But as officials looked closer, they saw two smaller groups of holes that could work the same way: a 10-hole loop and a 5-hole...