167.5236 Very Good
100.5097 Above Average
-3.7750 slightly biased towards defence
12.7824 biased towards physical
This defensive spread makes as big as possible a difference between PT and ST, allowing Weak Armor to be used against a wide variety of moves even without defensive investment. This spread can set up in the face of neutral physical attacks, but will crumble quickly to neutral special attacks, creating a nice risk/reward dynamic. The physical tankiness, maxed out within our parameters, makes Stealth Rock management very important, as it is often the difference between being able to set up on a neutral physical attack and being able to set up on a super effective physical attack. If you recall the typing discussion, this is exactly the reason we chose a SR-weak typing for. Here are some calcs to illustrate what this spread can accomplish with no defensive investment:
As you can see, the physical tankiness helps quite a bit with the typing, allowing it to survive many weak and even not-so-weak super effective attacks. This mitigates some of the weaknesses that the typing carries with it, and should make setting up stat boosts or support moves against physical attacks very doable. The Special Defense is not going to be good for much other than resisted attacks, however. Politoed's Scald + a Burn will always OHKO, although it (and many other special attackers) will have a difficult time switching in.
The offenses are balanced, allowing either side to be dangerous with boosting moves and allowing for mixed sets biased towards either side. SpA is higher because it lacks a 120 BP STAB, and to help sets utilizing physical moves along with HP Ice or HP Fire. Physical is still the star of the show here, due to the nearly inevitable Megahorn. Sets with mostly special attacks along with physical Fighting-type moves would also work well with these offenses. Going mixed will likely encourage a SpD reducing nature, further increasing the defensive imbalance (probably true of many spreads here). Considering our STABs and the fact that Fighting coverage has been suggested by BMB, the spread is designed to work for Bug/Psychic/Fighting/setup move and Bug/Psychic/Fighting/Hidden Power sets on either side of the attacking spectrum. While the attacking stats are not spectacular, it should have the coverage to hit a large portion of the metagame Super Effectively, and shouldn't need attacking stats much higher than these.
A Life Orb Megahorn can OHKO Scarf Politoed with SR and 2HKO Ferrothorn and SpD Jirachi. Zen Headbutt will cleanly OHKO Terrakion and Keldeo, while uninvested HP Ice or HP Fire can get OHKOes on Gliscor or Scizor. Physically-based mixed sets have enough power to threaten most of the metagame with reasonable coverage moves. Breaking Skarmory will be tough with physical sets, and Gliscor will probably be unbreakable without HP Ice or a physical Ice move.
A Life Orb set can 2HKO a large portion of the metagame. Even without HP Fire, Focus Blast would do a great job of dealing with most Steel-types. Scizor, Skarmory, Heatran, Forretress, and Genesect, will all have their main sets KOed by a combination of Stealth Rock, Psychic or Bug Buzz, and Focus Blast. The safe switch-ins to this set, such as Chansey and SpD Jirachi, will fall to a physical set. Chansey could even be dealt with by an uninvested Life Orb Close Combat.
As for the speed, I didn't think we needed to outrun tons of Scarfers at +1, but wanted enough speed that low SpD wouldn't just end up becoming a Rain weakness. Thus, I shot for outspeeding Rotom-W, so it can't revenge kill us at +1 using a Scarf. CAP4 actually has a trick up his sleeve for many of the Scarfers that might switch in to counter. Keldeo and Latios face a Super Effective STAB move to the face trying to switch in; Landorus and Genesect can switch in and threaten you, but thanks to immense physical bulk and Weak Armor, they risk giving you a game-changing setup should they U-turn while you don't switch. 90 Spe outspeeds unScarfed stuff at +1 and basically everything at +2, leaving a lot of room for different combinations of boosting moves and abilities; do you want to reach +2 atk +1 spe after a setup turn and weak armor boost, or +1 atk and +2 spe? Perhaps you'd rather ditch Weak Armor and try to set up multiple boosts behind your massive defense? These stats should work for just about any boosting move in the game, so it should do very well at sweeping on either side of the spectrum or at wall-breaking. The key is that you are forced to make tough choices that tend to push you towards one or another role. A mixed or special 4 attacks set should have the sheer coverage to threaten any switch-in, while sets that setup to +2 in either offense can sweep stall teams, but will have more counters. Sets that boost speed and an attacking stat simultaneously should sweep faster teams effectively but will need help with walls. This is in keeping with BMB's early statements that there should be a clear distinction between sets that can sweep and sets that break walls; this spread would render CAP4 able to do both, but not at the same time.
Just for refence, these are exactly Lucario's offensive stats (he also has 120 BP physical STAB and 90 BP Special STAB)