[Daryl]

Extensor Action is a Non-Accelerating Thrust. Use as much as you can. Although it doesn't Accelerate the Clubhead directly, it contributes to precision of the Accumulators.

Clubhead Lag (7-19) promotes even and steady acceleration, assuring dependable control of distance. The Power Package utilizes four types of Thrust:

1. Accelerating (Accumulators driving the Lever Assemblies)
2. Non-Accelerating (Extensor Action supplying Power Package Mass)
3. Acceleration Control (Lag Pressure Point sensing Clubhead Inertia)
4. “Centrifugal Acceleration” (Centrifugal Force pulling the Clubhead toward its In- Line condition)

Hmm?, there is that 4 Barrel Swing thing.