Rod Cross is a retired Associate Professor in Physics at the University of Sydney, Australia, but continues research into the physics of sport, especially tennis. His paper in the American Journal of Physics on the sweetspots of a baseball bat was voted as one of the top 75 papers in physics in the USA in 1998. He has published about 30 sports physics papers in scientific journals and has written extensively for USRSA's Racquet Tech and Racquet Sports Industry on the physical properties of tennis strings and tennis racquets. He is coauthor of The Physics and Technology of Tennis. Crawford Lindsey is the editor-in-chief of Racquet Sports Industry magazine and Racquet Tech Publishing. He is… also the web developer/master of www.racquettech.com, for which he has developed extensive software programs dedicated to racquet selection, customization, optimization and stringing. He graduated from Princeton University and was a product manager for squash and racquetball racquets as well as tennis and ski accessories at Head Sports. He is coauthor of The Physics and Technology of Tennis, author of The Book of Squash, contributor to The Science of Tennis CD-ROM, and author of numerous technical articles for Racquet Sports Industry and Racquet Tech magazines.