when you're playing a chord with a weird voicing and you know for the next chord you're supposed to flat the 5th or sharp the 9th or whatever, how do you quickly figure out which finger you're supposed to move?
i don't think about which fingers to move, i think about which notes to play. flat 5th means a tritone away from the letter name of the chord, sharp 9 is a minor third above the letter name of the chord