If yardage gains are among your aspirations for game improvement this year, TheStack is a worthy investment. The best news?

A few weeks ago a reader of my Golf IQ newsletter (which you can sign up for via Golf Digest+ right here), asked an interesting question. He was worried, in short, that one of his arms was so weak ...

Just how many yards can you gain off the tee after using TheStack swing speed training system for four months? Answer: A lot!