The cynical, borderline tactics that experienced players use to gain an advantage. Pulling shirts at corners, standing on feet, leaving a bit extra in a tackle, slowing the game down when ahead. Not cheating, exactly. Just operating in the grey area between the rules and the spirit of the game. Great defenders are all masters of the dark arts.
"One-nil up away from home, 88th minute: short corner, ball shielded at the corner flag by four bodies. The dark arts, executed to perfection."