This is the pertinent rule. The key is participation in "organized competition" that occurs more than one calendar year after high school graduation and prior to college enrollment.
(For the poster asking about hockey, there is an exception for hockey that appears to give a grace period until age 21 for pre-matriculation competition.)
The rule:
"14.2.3.2
Delayed Enrollment—Seasons of Competition.
14.2.3.2.1
Sports Other Than Men’s Ice Hockey, Skiing and Tennis.
In sports other than men’s ice hockey, skiing and tennis, a student-athlete who does not enroll in a collegiate institution as a full-time student in a regular academic term during a one-year time period after his or her high school graduation date or the graduation date of his or her class (as determined by the first year of high school enrollment or the international equivalent as specified in the NCAA Guide to International Academic Standards for Athletics Eligibility and based on the prescribed educational path in the student-athlete’s country), whichever occurs earlier, shall be subject to the following:
(a)
The student-athlete shall be charged with a season of intercollegiate eligibility for each calendar year
after the one-year time period (the next opportunity to enroll after one calendar year has elapsed)
and prior to full-time collegiate enrollment during which the student-athlete has participated in
organized competition per Bylaw 14.02.11.
(Revised: 4/29/04 effective 8/1/04)"
There are also now specific rules for track/cross country road racing but since these became effective after the fact in Ward's case, I'm not sure they have any application.
To wit:
"14.2.3.2.1.2
Track and Field and Cross Country.
A student-athlete who has participated in organized competition after the one-year time period (the next opportunity to enroll after one calendar
year has elapsed) and prior to full-time collegiate enrollment during a cross country, indoor track and
field, or outdoor track and field season (as opposed to general road racing events) shall be charged with
a season of competition in the sport in which the student has participated for each calendar year after
the one-year time period in which he or she participated in organized competition.
(Adopted: 4/29/10
effective 8/1/11; applicable to student-athletes who initially enroll full time in a collegiate institution on or
after 8/1/11)
14.2.3.2.1.3
Road Racing.
A student-athlete who has participated in road racing activities after the
one-year time period (the next opportunity to enroll after one calendar year has elapsed) and prior to
full-time collegiate enrollment shall be charged with a season of competition in each of the sports of cross
country, indoor track and field, and outdoor track and field for each calendar year after the one-year time
period in which he or she participate in organized competition.
(Adopted: 4/29/10 effective 8/1/11)"
http://www.ncaapublications.com/p-4322-2013-2014-ncaa-division-i-manual.aspx?CategoryID=0&SectionID=0&ManufacturerID=0&DistributorID=0&GenreID=0&VectorID=0&