which knuckles do I punch with for MMA? for most effect?

When anybody throws a basic punch Id say 95% of the force is delivered with the middle knuckle of the fist,regardless of style,the biggest difference I see are the two angles of a a fist,get a ruler hold it against your knuckles,on normal knuckles there's two angle,the outside shown here,

when you punch with the outside knuckles or three knuckles most of the force is still on the middle knuckle,but because the three knuckles slope away to the outside they cant be supported kinetically by the arm and this causes more rotation than damage. or you can punch with the inside of the middle knuckle here

when you punch with the inside knuckle or two knuckles most of the force is still on the middle knuckle,but its has a flatter surface to deliver it and the power is supported by the index finger and the arm behind it,making a considerable difference the effect and power delivered.
so there might be an inch difference from where your landing on your fist,but the effects and results can show miles of difference,the kinetic chain is the same to build power for each punch,but there is differences in how you finish the chain,this is another reason the two knuckles deliver more shockwave and reduce the chance of a boxers fracture,just remember modern boxing gloves teach you to hit with the outside of the knuckle.