A circular knitting machine, comprising: - a needle-holding cylinder having a plurality of longitudinal grooves arranged around a central axis (X-X) of the needle-holding cylinder; - a plurality of needles, each being housed in a respective longitudinal groove; - at least one yarn feed operatively associated to the needles; - actuating cams arranged around the needle-holding cylinder and movable with respect to said needle-holding cylinder around the central axis (X-X) for causing or allowing the movement of the needles along the longitudinal grooves so as to enable stitch formation by said needles; - a drive chain for each needle inserted into the respective longitudinal groove, located below the respective needle and operatively placed between the respective needle and said actuating cams; wherein said drive chain comprises: a sub-needle arranged below the needle; a selector arranged below the sub-needle, having at least one respective butt radially movable between an operating position, in which it is extracted so as to engage with respective selector paths defined by selector cams, and a non-operating position, in which it is retracted so as not to engage with said selector paths; at least one selecting device acting under control upon said selector for switching the latter into or retaining it in the operating position or the non-operating position; a punch arranged between the sub-needle and the selector, wherein a lower portion of the punch is engaged with the selector and an upper portion of the punch is engaged with the sub-needle, wherein the punch has a respective butt which can be engaged with respective punch-paths defined by punch cams; characterized in that, taking as reference the drive chain rotating with respect to the actuating cams around the central axis (X-X) in a sense of rotation (CW; CCW), the punch-paths comprise a tuck stitch ascent and a drop stitch ascent for each yarn feed, and wherein an inlet of the drop stitch ascent circumferentially precedes an inlet of the tuck stitch ascent; wherein the selector paths comprise a single track defining a first ascent and a second ascent placed in succession one after the other for each yarn feed; wherein the first ascent circumferentially precedes the second ascent; wherein the first ascent is operatively associated to the drop stitch ascent and the second ascent is operatively associated to the tuck stitch ascent. - a needle-holding cylinder having a plurality of longitudinal grooves arranged around a central axis (X-X) of the needle-holding cylinder; - a plurality of needles, each being housed in a respective longitudinal groove; - at least one yarn feed operatively associated to the needles; - actuating cams arranged around the needle-holding cylinder and movable with respect to said needle-holding cylinder around the central axis (X-X) for causing or allowing the movement of the needles along the longitudinal grooves so as to enable stitch formation by said needles; - a drive chain for each needle inserted into the respective longitudinal groove, located below the respective needle and operatively placed between the respective needle and said actuating cams; wherein said drive chain comprises: a sub-needle arranged below the needle; a selector arranged below the sub-needle, having at least one respective butt radially movable between an operating position, in which it is extracted so as to engage with respective selector paths defined by selector cams, and a non-operating position, in which it is retracted so as not to engage with said selector paths; at least one selecting device acting under control upon said selector for switching the latter into or retaining it in the operating position or the non-operating position; a punch arranged between the sub-needle and the selector, wherein a lower portion of the punch is engaged with the selector and an upper portion of the punch is engaged with the sub-needle, wherein the punch has a respective butt which can be engaged with respective punch-paths defined by punch cams; characterized in that, taking as reference the drive chain rotating with respect to the actuating cams around the central axis (X-X) in a sense of rotation (CW; CCW), the punch-paths comprise a tuck stitch ascent and a drop stitch ascent for each yarn feed, and wherein an inlet of the drop stitch ascent circumferentially precedes an inlet of the tuck stitch ascent; wherein the selector paths comprise a single track defining a first ascent and a second ascent placed in succession one after the other for each yarn feed; wherein the first ascent circumferentially precedes the second ascent; wherein the first ascent is operatively associated to the drop stitch ascent and the second ascent is operatively associated to the tuck stitch ascent. a sub-needle arranged below the needle; a selector arranged below the sub-needle, having at least one respective butt radially movable between an operating position, in which it is extracted so as to engage with respective selector paths defined by selector cams, and a non-operating position, in which it is retracted so as not to engage with said selector paths; at least one selecting device acting under control upon said selector for switching the latter into or retaining it in the operating position or the non-operating position; a punch arranged between the sub-needle and the selector, wherein a lower portion of the punch is engaged with the selector and an upper portion of the punch is engaged with the sub-needle, wherein the punch has a respective butt which can be engaged with respective punch-paths defined by punch cams;