Major thirds tuning hand is stationary and the fingers move, each finger being responsible for one fret. Consequently, three hand-positions (covering frets 1–4, 5–8, and 9–12) partition the fingerboard of classical guitar, which has exactly 12 frets. Only two or three frets are needed for the guitar chords—major, minor, and dominant sevenths—which are emphasized in introductions to guitar-playing and to the fundamentals of music. Each major and minor chord can be played on two successive frets on three successive strings, and therefore each needs only two fingers. Other chords—seconds, fourths, sevenths, and ninths—are played on only three successive frets. For fundamental-chord fingerings, major-thirds
Rule of thirds (military) Rule of thirds (military) The rule of thirds is a rule of thumb used when planning for the deployment and usage of a military organisation, according to which one third of the total military forces involved should be available for operations, one third should be preparing for operations and the final third, having been on operations, should be recuperating. Ideally, units and individuals regularly will rotate through each of the three phases. Different nations and militaries will vary the rule of thirds according to their own financial and manpower situations. At times of financial constraint, rather than increasing the total