OH MY ****ING GOD DUMB PEOPLE STOP POSTING SETS THAT GIVE SCIZOR EVSPREADS
Fixed. People who don't understand things like Priority and Weaknesses should leave the EV spread mechanics to the experts. Speed is not needed on Scizor due to Bullet Punch and (if you decide to use any of them) Quick Attack, Feint, or Vacuum Wave.
Sp.Def EVs are somewhat a waste due to a QUAD FIRE WEAKNESS and a popularity of having so many Pokemon that learn Flamethrower. One shot without a Focus Sash will ruin you anyway due to low base HP (Base 70 gives you a maximum of 344 HP), but defending against priority attacks (aside from V.Wave) entails pouring on Defense EVs.
Even then, you would be an idiot to try anything except running away from a Fire Type with Scizor. However, this leads into a potential counter-strategy of sending in Zoroark to appear as a Flame Body Ability Fire Type (such as Volcarona or Magmortar) then hitting a fleeing Sciz' with Pursuit.
Tackling a threat like Scizor means you have to know how to properly use it yourself. When you understand the intricacies, you can counter it. Luck plays a very small part unless you can mess with your opponent's head.