Looking at the competition fields, it appeared that they used brand new foam mats. In contrast, the practice fields appeared to have used foam mats that were likely used throughout this season; which means that the mats were possibly sprayed with anti-static spray at previous events.
Originally Posted by FTC4318
If what another poster said is correct, the spray would be effective for up to 30 days after application.
Maybe the difference between the practice fields and competition fields had more to do with that than the underlay on the gym floor? Which would then really call into question the tournament directors' decision not to use anti-static spray. Just a thought.