I once thought there was a rule of thumb that for each 1/2″ of shaft length change, the lie should be adjusted 1*. Recently, I read that 1* may be a bit much and that 1/2* might be a better rule of thumb. No question that using a launch monitor or even a lie board is best but I am just looking for a rule of thumb confirmation..
Rule of thumb has never changed. It is for every 1/2″ of length change, the lie adjustment would be 1 degree. That being said, because length changes can alter a players swing dynamic, we always recommend dynamically fitting the lie after the length change and not to just assume the 1/2″ to 1 degree relationship will always be absolute.