Modelling Playing Quality – Ball Roll

Looking further into how to develop an all encompassing model which can be used to help manage turfgrass surfaces in a sustainable way, it’s clear there will need to be numerous sub-models for experimenting with different aspects of a complete system model. Linking the different sub-models will then be a challenge.

I was initially thinking of carrying out the required calculations for the sub-models using php, however, I revisited the Jquery plugin Calx which can mimic Excel to a certain degree and allows for some useful formula coding to be written into a web page, so for now I’ll stick with that as the tool for carrying out calculations.

For my first sub-model I’ve included the relationship between grass height (mowing height), ground cover and whether the ground is dry or wet.

The data and formulae for the correlations have been based on research in the 1990s, although the sub-model will need to be enhanced to include an option for a manager to increase / decrease the results to better reflect their particular situation.

This first sub-model is can be found at

Sub-model Ball Roll

Sub-model Ball Roll

Now that I’ve created a working sub-model I think the next step will be to map out, visually, a range of cause and effect sub-models and provide an indication of how they might be linked into a system.


Baker, S.W., (1990) ‘Performance standards for professional soccer on artificial surfaces’, Journal of the Sports Turf Research Institute, Vol. 66, pp42-69

Baker, S.W., Gibbs, R.J., & Adams, W.A. (1992) ‘Case studies of the performance of different designs of winter games pitches. I. Playing quality and usage’,  Journal of the Sports Turf Research Institute, Vol. 68, pp20-32

Richards, C.W. &  Baker, S.W. (1992) ‘Technical note. The effect of sward height on ball roll properties for Association Football’, Journal of the Sports Turf Research Institute, Vol. 68, pp124-127

(2004), IOG Performance Quality Standards: Football (2nd Edn 2.1), The Institute of Groundsmanship

Chris Gray, 14th March 2017 (updated 16th March 2017)