I am looking to purchase a decent (old) "88-note" player piano.  After
experience with all the other pianos I have, I've decided that one of
my primary considerations should be the type of 'auto-tracking'
mechanism on the piano.  So far, I have run across:

1: None
2: None, but tracker bar can be manually adjusted as the roll is playing
3: Ears which sense the edge of the paper
4: Fingers which sense the edge of the paper
5: Holes in the tracker bar that sense the edge of the paper.

There seem to be pros and cons to each of these methods.  For
instance, it seems as though 'ears' could much more easily damage
the edge of the roll - holes sensing the edge of the paper would
not work well if playing rolls with very soft or torn edges.

From what I can tell, the "fingers" method seems to be the best,
but I've only seen this on a Franklin Ampico.

I'm interested in seeing a discussion of the various methods and
recommendations, particularly in regards to purchasing an 88-note
player.  Are there any other systems?  Is one system better than
another?

John W Miller

 [ I like best the single or double ears of the Aeolian Pianola,
 [ because (1) the force on the paper is minimal, and (2) the
 [ edge-sensing assembly is easily adjusted should the paper roll
 [ be punched off-center.  Most other mechanisms have little or
 [ no provision for immediate adjustment of the automatic tracking
 [ system by the Pianolist.  Besides, the player action in an Aeolian
 [ vertical piano is very pleasant to maintain.  :-)  -- Robbie