I switched to 3 blade only becuase the store was out of 2 blade...shot 3 does and 1 buck with them....every shot the blades were retained behind o-ring before the shot...all but 1 didnt pass through....all 4 deer died within 60 yrds...all were shot either broadside or slight quartering away...that proved to me that 2 blades have better penetration...32" draw--72lbs on bow Matthews Conquest..so I am pretty sure its not a kinetic issue..think what happens is the 3 blade version packs up with much more fat/hair on way in...and that slows head down....2 blades get alot less hair/fat wedged into the furrel where blades sit/deploy from....just something I leanred from my setup....but I swear by the 2 blades...tons of blood and deer die FAST