Allowing winter play is always a tough decision for golf course superintendents. Balancing agronomic concerns with golfers (and revenue) is a tough decision.  Below is a ranking from least injurious to most.

1) Play on dry unfrozen soil - Although wear injury is always a potential problem, this situation will result in the least damage.

2) Play on frozen soil - Most likely will result in wear injury to the turf but little soil compaction.

3) Play on wet, unfrozen soil - The potential damage under this scenario is significant soil compaction can occur but less wear injury.

4) PLAY ON A THAWING SOIL (UNFROZEN (WET) ON THE SURFACE, FROZEN BELOW) - This situation can result in both wear injury and soil compaction and play should be avoided.