Well, I'd like to disagree in quantity not in quality with that statement.
Just my humble opinion, but the "sport" is most certainly for the rider.  
We humans chose to invent this thing called endurance riding/racing, and 
to ask our horses to perform at high levels for us when they might prefer
to be lazing around in pasture.  The horse does by far most of the 
work--and may even enjoy it--but it is still a team effort.  I haven't 
heard of any horses getting completions in races without their riders. 
(If anyone knows how to get one to do that, let me know and I'll start 
training Charlie right now! :-) )  Biggest credit goes to the horse, 
team leader/manager credit goes to the rider.  And lots of credit to the 
support teams!
-Sallijan
 and Charlie
------------------------------------------------------------------------
Sallijan Snyder, Santa Clara, CA   | ==> I am not a speaker-for-Intel.
(408)765-9068 wrk (408)629-5909 hm | "Give me land, lots of land
Internet: jsnyder@td2cad.intel.com |  Under starry skies above--
  or      sallijan@ix.netcom.com   |     Don't fence me in!"
     *IZCC #42, ZONC #97043*       |		--Cole Porter