Copied from an old Smogon thread: The 24 Def EVs ensures that Scizor's Bullet Punch is always a 3HKO and Jirachi's Iron Head a 4HKO. Ideally, you will not want to be facing Scizor when it used Pursuit, as that means your probably lost a Pokemon! However, Scizor's Pursuit is still a 2HKO on the Substitute which allows you to Substitute and Charge repeatedly. The heavy investment in Special Defense may seem excessive, but allows you to carry out the same procedure against a Choice Scarf Heatran locked into Dragon Pulse, as it will never OHKO your Substitutes. The Speed is necessary to outspeed Skarmory and kill it before it has a chance to do anything. Do not try to set up on Skarmory, as Charge Beam will fail to OHKO the Steel bird and Magnezone will be met with a swift Whirlwind or an extra layer of Spikes. The remaining EVs were placed into Special Attack to pack a bit more punch.
I just got an IV check code so that I could make sure that I had everything correct on all of my pokemon. It turns out, I had a couple other errors I didn't know about. One of which makes Poliwag's HP Grass 68 rather than 70. I'm sorry AGAIN. I will be re-breeding him the first chance I get (probably Monday) and EVing him myself. I'll VM you when I have him ready and I'll send you a copy. This sucks but I'm glad you made me think to double check everything. Just wanted to let you know as soon as I could.