An apparatus, comprising: (a) a body; (b) a shaft extending from the body; and (c) an end effector (212, 312, 412, 512) in communication with the shaft, wherein the end effector is operable to compress, staple, and cut tissue, wherein the end effector comprises: (i) an anvil (218, 318, 418, 518), wherein the anvil is movable between an open position and a closed position, wherein the anvil has a distal tip (219, 319), wherein the end effector defines a longitudinal axis intersecting the distal tip of the anvil when the anvil is in the closed position, and (ii) a cartridge (237, 337, 437, 537), wherein the cartridge defines a sight line extending along a distal surface of the cartridge from a first side of the cartridge toward the anvil, wherein the first side of the cartridge is opposite to the anvil, wherein the distal surface of the cartridge is neither parallel to nor perpendicular to the longitudinal axis, wherein the sight line intersects the longitudinal axis near the distal tip when the anvil is in the closed position, wherein a segment of the sight line and a segment of the longitudinal axis define an angle θ, wherein the segment of the sight line is on a cartridge side of the longitudinal axis, wherein the segment of the longitudinal axis is distal to the sight line, wherein the angle θ is larger than 90°; and characterised by at least one of: the anvil comprising an anvil ball groove and a distal tip of the cartridge comprising a cartridge ball tip, wherein at least a portion of the cartridge ball tip is configured to fit in the anvil ball groove; and the cartridge comprising a cartridge ball groove and the distal tip of the anvil comprising an anvil ball tip, wherein at least a portion of the anvil ball tip is configured to fit in the cartridge ball groove. (a) a body; (b) a shaft extending from the body; and (c) an end effector (212, 312, 412, 512) in communication with the shaft, wherein the end effector is operable to compress, staple, and cut tissue, wherein the end effector comprises: (i) an anvil (218, 318, 418, 518), wherein the anvil is movable between an open position and a closed position, wherein the anvil has a distal tip (219, 319), wherein the end effector defines a longitudinal axis intersecting the distal tip of the anvil when the anvil is in the closed position, and (ii) a cartridge (237, 337, 437, 537), wherein the cartridge defines a sight line extending along a distal surface of the cartridge from a first side of the cartridge toward the anvil, wherein the first side of the cartridge is opposite to the anvil, wherein the distal surface of the cartridge is neither parallel to nor perpendicular to the longitudinal axis, wherein the sight line intersects the longitudinal axis near the distal tip when the anvil is in the closed position, wherein a segment of the sight line and a segment of the longitudinal axis define an angle θ, wherein the segment of the sight line is on a cartridge side of the longitudinal axis, wherein the segment of the longitudinal axis is distal to the sight line, wherein the angle θ is larger than 90°; and characterised by at least one of: the anvil comprising an anvil ball groove and a distal tip of the cartridge comprising a cartridge ball tip, wherein at least a portion of the cartridge ball tip is configured to fit in the anvil ball groove; and the cartridge comprising a cartridge ball groove and the distal tip of the anvil comprising an anvil ball tip, wherein at least a portion of the anvil ball tip is configured to fit in the cartridge ball groove. (i) an anvil (218, 318, 418, 518), wherein the anvil is movable between an open position and a closed position, wherein the anvil has a distal tip (219, 319), wherein the end effector defines a longitudinal axis intersecting the distal tip of the anvil when the anvil is in the closed position, and (ii) a cartridge (237, 337, 437, 537), wherein the cartridge defines a sight line extending along a distal surface of the cartridge from a first side of the cartridge toward the anvil, wherein the first side of the cartridge is opposite to the anvil, wherein the distal surface of the cartridge is neither parallel to nor perpendicular to the longitudinal axis, wherein the sight line intersects the longitudinal axis near the distal tip when the anvil is in the closed position, wherein a segment of the sight line and a segment of the longitudinal axis define an angle θ, wherein the segment of the sight line is on a cartridge side of the longitudinal axis, wherein the segment of the longitudinal axis is distal to the sight line, wherein the angle θ is larger than 90°; the anvil comprising an anvil ball groove and a distal tip of the cartridge comprising a cartridge ball tip, wherein at least a portion of the cartridge ball tip is configured to fit in the anvil ball groove; and the cartridge comprising a cartridge ball groove and the distal tip of the anvil comprising an anvil ball tip, wherein at least a portion of the anvil ball tip is configured to fit in the cartridge ball groove.