Half position is the one nobody teaches early and everybody eventually needs. The hand slides back toward the scroll until the first finger is only a semitone above the open string, which puts the flat second degree of a key under a finger instead of behind one. It feels wrong because it is unfamiliar, not because it is difficult.
The frame, string by string
Every pitch below is computed from the instrument's real open-string tuning plus the one thing this position declares — that its first finger sits 1 semitone above the open string. The four fingers then span a perfect fourth (5 semitones) without the hand moving:
| String | Open | 1st finger | 2nd | 3rd | 4th |
|---|---|---|---|---|---|
| G string | G3 | A3 | B3 | C#4 | — |
| D string | D4 | E4 | F#4 | G4 | — |
| A string | A4 | B4 | C#5 | D5 | — |
| E string | E5 | F#5 | G5 | A5 | — |
Across all four strings this position reaches 28 distinct pitches, of which 12 belong to D major. A dash means the scale simply has no note under that finger here — which is information, not an omission: it is exactly where a different key would put one.
Getting here from first position
The hand moves back by 1 semitone. That last fact is what makes a shift learnable: you are not aiming at an unmarked distance, you are aiming at a pitch you already know.
Practise the move on one string with the bow sounding continuously, so you hear the slide rather than hiding it. Then do it silently, then do it fast. The daily drills hold the frame still first, which is the prerequisite.
When to use it
The hand pulled back toward the scroll. Rare, awkward, and the only way to reach the flat second degree of some keys without a shift. Check it against a real tune: the tune maps show which positions each one actually needs, and several need fewer than you would expect.