Strings (tennis)
In tennis, the strings are the part of a tennis racquet which make contact with the ball. The strings form a woven network inside the head (or "hoop") of the racquet. Strings have been made with a variety of materials and possess varying properties that have been measured, such as dynamic stiffness, tension retention, thickness (gauge), string texture (shape of the string), and rebound efficiency.
Guitar picking
The pros of each guitar picking style are indirectly correlated to the cons of the other.Fingerstyle players use up to four (rarely five) surfaces to strike string independently. However, that does not equate to four plectrums, since plectrums can more easily strike strings on both up and downstrokes—which is much more difficult for fingers.To achieve Tremolo effects, varied arpeggios, and rapid, fluent scale passages, the player must practice alternation, that is, plucking strings with a different finger each time. 
Using p to indicate the thumb, i the index finger, m the middle finger and a the ring finger, common alternation patterns include: