RE: 3 Blade Muzzy or 4 Blade Muzzy? What's the big difference?
 

I strongly agree with what goat said. Though they are two different broad heads, and the 4-blade might cut better while the 3 blade might fly better, if put the arrow where you want it to be, then the deer, or what every else you are shooting at, will die and die close. Shot placement is the key.