What if you could measure the quality of a field during maintenance and in a way that is very close to what the player experiences? A trial with special insoles in the shoes of the field manager of the Johan Cruijff Arena in Amsterdam should establish whether this can be the future for sports field management.
One of the biggest challenges field managers and greenkeepers face these days is converting the subjective experience of players and coaches into measurable data. What does a player’s statement that “The field is too hard” or that “passes did not arrive because the field is too slippery” say about the condition of the field? And what value should you attach to that statement when you correlate it with the final result of the game? Modern techniques increasingly enable field managers to objectify those subjective opinions. However, the Johan Cruijff Arena is keen on pushing the boundaries and has established a field lab to test new developments. Researcher Joep van Cranenbroek of HI Sports and Holland Innovative tests the next generation of innovations for sports field management. The most recent step, literally, is the use of special pads with sensors. “These insoles with pressure sensors are worn in the shoe by the field manager. Long-distance runners are already using them to obtain feedback on their gait as they run so they can adjust their running pattern or rhythm.”
Simple principle
Van Cranenbroek’s principle is simple: while the field manager is busy trimming the grass, the sensors in the insoles collect data on various parameters such as shock absorption and energy recovery while he is walking the field. “To calibrate the sensors, we ask the field manager to first walk on a paved surface,” says van Cranenbroek. “Once calibrated, the only thing the field manager is expected to do is walk on the field in a way that is normal and familiar to him. This helps the self-learning software to filter the correct data from the incoming data.” GPS technology is used to capture the exact location of the measured value. “The data is automatically fed through a cell phone connection directly into the database, from where the field condition is monitored and analysed.” The field management team of the Johan Cruijff Arena has no shortage of data. “We have sensors in the field and on our grass cutting equipment. We also receive input from the weather station, we analyse the images taken by the many cameras in the stadium and we receive input from other sensors that measure all kinds of other things, such as the outside temperature. All that data ends up in a huge data lake,” notes Paul Baas of De Enk Sport & Groen, the company that is contracted to maintain the field.
Savings costs
According to van Cranenbroek, it is not the data collected but the savings achieved that will be the biggest benefit of the technology. “Testing the field to establish its condition, as well as entering the collected data into the system is a time-consuming process. In addition, opinions are often subjective. Therefore, our goal is to make these tests obsolete and to objectify the collected data that are fed to the data lake automatically.” At present, the field of the Johan Cruijff Arena is tested at least three times for every match. “The first time we do that is about three days before kick-off. The information we then receive should help us determine which activities should be prioritised. The second test happens on match day to determine whether we have actually achieved the intended quality. Finally, we measure that quality again the day after the game to better understand the input we receive from the players,” notes Roy van Dijk, who works together with Baas. Various manuals by international football associations on field testing state that field managers should reserve up to two hours when measuring the quality of a field. “To save some time, we now often only measure at four instead of the required seven spots,” van Dijk admits. Should van Cranenbroek manage to conclude the test with the insoles successfully, he could save the field managers in Amsterdam at least six hours work for any home game. As the venue is also used by the Dutch national team, the savings could be significant. “All in all, you can save 80% of the current costs,” he notes.
Initial phase
The accuracy of the technique is currently 83%. Van Cranenbroek notes that the development is still in the feasibility phase and that the first model will be launched in the coming months. “We have only recently started fine-tuning the technology. One of the challenges we have identified already is the roof of the stadium. Sometimes it blocks the GPS tracker from working properly.” Another interfering factor that has been identified is the backing of the Playmaster hybrid system. The solid sections that hold the synthetic yarn fibres that support the field, provide a different reading compared to the sections where the field only has soil underneath. Another problem is that the insoles must be worn inside the shoe itself. “Occupational health and safety legislation obliges us to wear sturdy shoes that are not really known for their flexibility. The lack of flexibility makes it a bit more difficult for the sensors to register everything accurately,” says Van Dijk.
Another tool
Van Cranenbroek is confident that it is only a matter of time before the various challenges have been eliminated. “We must not forget that we should primarily see the insoles as a possible tool for the field manager. It should help the field manager to gain insight into his fields with more data and to be able to make decisions. Sports field management remains human work because, in the end, you also need eyes and ears on the field.”
According to van Cranenbroek, the information should predominantly be seen as a means to better predict which activities are needed to prepare the field correctly.
Although it all sounds very futuristic, it seems that it is only a matter of time before this (sensor) technology also becomes part of the package for the field manager and greenkeeper. The last few steps to make this become reality are currently being taken.
This article was commissioned by Fieldmanager Magazine from the Netherlands