Hold the mandolin back to your stomach and look at the space between the strings and the fret board. Line up the strings, and then take notice of the space between the strings and the fret board, from the first fret to the strings the space between should be about 2 mil, and on the 12th fret about 2 ½ to 3 mil. You will then have an idea of if it's playable or if the necks in warp or twist