Demetri, 

The amount gained or lost will vary per player.  There is usually a gain in club head speed when adding extra length (over what they were fit for), but a big issue for these players is they see their dispersion widen.  In most cases, players can become more inconsistent.  When decreasing the overall length (less then what they were fit for), the player, again, may start to see more inconsistencies and reduced ball speed.  

Cameron

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