The tones are quite useful to practice with and are worth the cost of the book IMO - especially for swingers. Tempo (rhythm) is a huge part of the swing that most people do not pay enough attention to and this is a great tool for learning.
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"Support the On Plane Swinging Force in Balance"
"we have no friends, we have no enemies, we have only teachers"
Simplicity buffs, see 5-0, 1-L, 2-0 A and B 10-2-B, 4-D, 6B-1D, 6-B-3-0-1, 6-C-1, 6-E-2
Tour Tempo is a fantastic tool. Just understanding the word Tempo can help.
I do not particularly care for the mechanics presented but that's just me. The other problem I found was that it takes a great deal of educated hands to be able to handle the 3:1 ratio. I would suggest to anyone beginning this that they start with chip shots so as not to strain the wrists too much.