Perfect liver shot is a KO punch (hard left hook) Perfect Solar Plexis can knock you down and wind you but if your tough you can get up from it... - rarely knocks you down - uppercut or straight punch will do it.... Most boxers just attack it with the jab. Kidney hurts but can't really be landed in a boxing match
Solar Plexus doesn't hurt as much as it just completely knocks the wind out of you. The other two hurt like ****. On par with each other. Kidney shots are illegal, though.
A liver shot is worse than an uppercut to the groin! The pain is far more intense im not kidding. Liver shot all day.