[magnets]

The text "CATCH: the event when a BALL SCORED over the TRUSS by a ROBOT’S ALLIANCE partner is POSSESSED by that ROBOT before contacting the carpet, the ROBOT which SCORED the TRUSS, or a HUMAN PLAYER."
can mean two things

1.) a catch is when a "BALL SCORED over the TRUSS by a ROBOT'S ALLIANCE partner is POSSESSED by"

a.) "that ROBOT before contacting the carpet"
b.) "the ROBOT which SCORED the TRUSS"
c.) "or a HUMAN PLAYER"
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2.) a catch is when a "BALL SCORED over the TRUSS by a ROBOT’S ALLIANCE partner is POSSESSED by that ROBOT before contacting the"

a.) "carpet"
b.)"the ROBOT which SCORED the TRUSS"
c.) "or a HUMAN PLAYER"

Two is more likely, but it's still really ambiguous.