This season seems to be the introduction more  subtle changes and breaks from the traditional symmetry found in past formations. Where formations were originally based on the golden mean, an introduction to a theorem as discovered by Gerald Hawkins or alignment to historic location, as I look back over this season, I am more drawn to the imperfections being introduced and have sent some diagrams to illustrate: 

Ripley - there appears to be a change in the length of the last two arcs on the opposing sides. Beckhampton  - the curvature of the formation to follow the tramline, based on the size of the arc, where would the centre be ? Clatford bottom - an offset of the central circle Avebury Trusloe - gaps in the formation, & pathways or tracks Silbury Hill - tangency of formation to hill

 As much as the diagrams done so far give a general concept to the formation, I feel that there is a specific  reasoning behind these subtle changes that we might miss without careful formation measurement. I would volunteer to do this if I was a portion of the globe closer, but can only hope that others might consider this a worthwhile endeavour. I can volunteer to prepare diagrams if individuals send the measurements. In the past field reports included locations by map, measurements, alignment to north or historic items, direction of lay. I would hope that all researchers or crop circle discoverers might be able to take the time to share this information, as the combined information only adds more intrigue to the subject.