No need to be in a jam when watching  Sometimes people come to
watch roller derby and have no idea what's happening. This does
not keep them from enjoying it -- chaos can be entertaining --
but here are some basics that will help unlock the mystery of
who wins the national title.  It's a bout: It's not a game or a
match but an old-time-sounding bout. Each team has five players
in tricked-out quad roller skates on the floor for each two-
minute jam. The two with the stars on their helmets are called
jammers, and they are the only ones who can score points. There
are two 30-minute halves.  On a flat track: The modern version
of roller derby is on a flat track, mostly for reasons of
convenience. There are two horizontal lines on the track. The
eight blockers, or the pack, line up behind the pivot line, and
the two jammers behind the jam line. There are two whistles --
the first starts the pack and the second starts the jammers. The
jammer who gets through the pack first is called lead jammer.
Playing the hits: T