Watch tournaments and you'll see all manner of leg kicks, calf kicks, shin kicks et cetera. If only, y'know, they were effective. A combination of things afflict the application of foot sweeps: lack of information, poor teaching protocol, lack of movement created by the attacker beforehand, lack of footwork, posture, balance, et cetera.
Relentlessly attacking foot sweeps against a stationary, defensive opponent will yield few takedowns to be sure. For me to sweep an opponent, I must catch them moving, preferably as their foot just about hits the mat. In Jiu-Jitsu, due to defensive posture, a blocking style usage of the foot will yield far more prodigious results.
Resist the urge to simply pick up their leg with your leg. If they are heavy on the lead leg, or their head/weight is over their lead leg, it simply will not work. It's basic physics. Block the leg and drive them past it and the leg will become light as they move away, allowing you to pick up the foot/knee et cetera.
Relentlessly attacking foot sweeps against a stationary, defensive opponent will yield few takedowns to be sure. For me to sweep an opponent, I must catch them moving, preferably as their foot just about hits the mat. In Jiu-Jitsu, due to defensive posture, a blocking style usage of the foot will yield far more prodigious results.
Resist the urge to simply pick up their leg with your leg. If they are heavy on the lead leg, or their head/weight is over their lead leg, it simply will not work. It's basic physics. Block the leg and drive them past it and the leg will become light as they move away, allowing you to pick up the foot/knee et cetera.