The term “dead spot” is frequently mentioned within the basketball community, yet there is little consensus on its definition. In this blog post, we will explore the concept of dead spots on basketball courts, drawing from the insights shared by Paul W. Elliott, PhD, PE in his article at https://asetservices.com/what-is-a-dead-spot-on-a-basketball-court/.
Dr. Elliott, a designer and engineer with over 25 years of experience in the sports surface market, begins by discussing how floors are tested in the lab. Rebound properties are assessed by comparing the height achieved during a rebound to that of concrete, with no consideration for sound, vibration, or feel. Lab tests generally use a basketball with 5-6 psi pressure, lower than the 7-9 psi recommendation for most balls. Given these testing standards, defining dead spots based on rebound height seems logical.
Players experience multiple sensory inputs while dribbling a basketball, including sound, vibration, and rebound height. Dr. Elliott’s analysis of data collected over 20 years ago revealed that a change in any of these factors often leads players to perceive a lower rebound height. Tone or sound had a higher correlation with players’ perceptions than actual rebound height.
With this information in mind, a dead spot can be defined as an area where the rebound height is significantly different from the rest of the playing surface. This definition helps create a common understanding among all parties involved. Some floor designs may feel “dead” overall, but if they are uniformly consistent, they don’t have dead spots.
But what does “significantly different” mean? Industry standards like ASTM F2772, EN 14904, FIBA, and MFMA allow rebound levels to deviate by up to 3% from the average. This means that a 6% deviation in rebound height (both above and below the average) is acceptable under these standards. Consequently, areas with rebound heights more than 6% away from the maximum value are considered dead spots.
Dr. Elliott advises that rebound levels 7% to 9% below the maximum can be considered marginally dead, and facilities should weigh the pros and cons of any repairs. Rebound levels 10% or more below the maximum are considered severe dead spots and warrant repair, though field testing and repairs will depend on the project’s specifications.
It’s essential to note that the issue might not always be dead spots; hard spots can also cause abnormally high rebound levels, requiring the repair of those areas instead.
Lastly, Dr. Elliott mentions that the difference between dead and non-dead areas is magnified as ball inflation pressure increases, exacerbating the problem.
To read Dr. Paul W. Elliott’s article click here: https://asetservices.com/what-is-a-dead-spot-on-a-basketball-court/ and if you’re experiencing dead spots or having other issues with your your Gym floor give us a call at (406) 549-1900.
