The putting green bobble test in practice

This chart shows almost a full season of bobble test measurements from Hazeltine National GC.

I discussed measurements of smoothness and trueness of ball roll in this video, and I mentioned that I use and recommend the bobble test as a way to make these measurements.

When the score is 8 or above, it’s essentially a perfect roll. The ball is tracking on the line it started on, there are only isolated chatter events that don’t deflect the ball off that line, and if there is any snaking, it is minimal, barely detectable, and at the end of the roll.

I made this chart to highlight three things related to these measurements.

  1. The bobble test is an easy way to find if the greens are rolling at an acceptable level for a particular course and time of year.

  2. Once that level is achieved, the score is not so important. One can just check that the greens are meeting the standard, and start recording data again when disruptive work is done to the greens again.1 The roll was checked from late June all through July, but it was not necessary to record the number because there was no snaking and almost no chatter.

  3. The bobble test makes it easy to assess the amount of disruption, and the time it takes to recover, from work that disrupts the surface such as topdressing, verticutting, solid-tine cultivation, DryJect, hollow-tine cultivation, and the like.

  1. I’m an advocate for doing as little disruptive work as possible, while still doing all that is essential. Measurements of surface performance are critical for the evaluation of the essential work. I explained this in the “Flying Blind” movie. ↩︎