Hi!
As the rule says! The servo arm should be as short as possible and the control arm as long as possible! That's the fact!
That way you get the least play. This is despite what kind of linkage you use, ball link, Z-bend or what ever.
This could easily be seen . Put the linkage rod at the center of the servo arm (in theory, as this is kind difficult to do in practice ) and you get 0 degrees of play in the elevator surface (theoreticly)...the further out you go on the servo arm the more play you get in the elevator surface.( with the same control arm lenght) if you on the other hand shorten the control horn so much as nothing of it protudes above the hinge line you will get lots of play.
As pictures below show.
Short servo arms...and long control arms (on ailerons and elevator) that way you minimize play!
