https://community.usms.org/swimming/f/general/4680/zirconium---rate-vs-lengthZirconium, I've been posting to many threads that are redundant so I'm going to steer you to some old threads that hopefully will help you. Please go to Theories - a new look to an old thread #1 and #7 then go to EVF Teaching the type in Earlyen-USTelligent Community 12