Some years ago, on a fine December day, I was at this beautiful golf course in southwestern China. The tees, fairways, and greens are creeping bentgrass. From the tee, I had the view above. But when I got to the fairway, I was surprised to look down and see this pattern.

In fact, there were a lot of cup cutter plugs, lined up one by one, on this fairway.

The mystery is this: why are there cup cutter marks in the fairway?

The correct answer was given in quick succession by @GreatManDan and then soon after by @gossturf.

@asianturfgrass Hydraulic oil would be my first option.

— DG (@GreatManDan) August 19, 2014

@asianturfgrass @gord_mckie repairs to a hydro leak?

— Jason Goss (@gossturf) August 19, 2014

What I found especially interesting was just how many plugs it took to make this repair. The diagonal across the fairway was about 175 yards in length. With each plug 4.25 inches in diameter, that would require 1482 individual plugs to make the repair.