Hey guys. This is an update post on my part, pretty much highlighting any new moves that have been brought up, haven't been discussed by me, or are being argued about since my first initial post with my calculations.
Volt Tackle: This seems to be getting a lot of steam behind it recently. I'm not going to be the guy that shoots it down due to power at all (I'm not 100% against it). Therefore, I'm going to go neutral in the way I handle talking about this. We should first run some calculations in order to determine what exactly it will do to expected targets as compared to similar moves, and what else will be affected by it outside of what it intends to ounter. Suicune seems to be the first and main target, so we'll run calcs on it. Here's some calculations. Note that this is 252 Atk/252 Spe with a Neutral nature for CAP10 for offensive calculations, and the same for Defensive:
Volt Tackle vs. Crocune: 61.4% - 72.8% (2HKO)
Volt Tackle vs. Offensive Suicune: 98.8% - 116.4% (OHKO)
Volt Tackle vs. SubCune: 84.9% - 100% (OHKO most of the time after SR)
Volt Tackle vs. CMShuffle/Sleep Talk: 61.4% - 72.8% (2HKO)
ThunderPunch vs. Crocune: 38.6% - 46% (3HKO on average)
ThunderPunch vs. Offensive Suicune: 62% - 73.7% (2HKO)
ThunderPunch vs. SubCune: 53.3% - 63.3% (guaranteed 2HKO after SR)
ThunderPunch vs. vs. CMShuffle/Sleep Talk: (3HKO on average)
+2 Surf vs. CAP10 (CroCune): 27.1% - 31.8% (4HKO)
+4 Surf vs. CAP10 (CroCune): 40.6% - 47.9% (3HKO)
+1 HP Electric vs. CAP10 (Offensive): 33.4% - 39.5% (3HKO)
+2 HP Electric vs. CAP10 (Offensive): 44.7% - 52.8% (potential 3HKO)
What we've gotten from the calculations: Volt Tackle is never necessary to take out the standard sets of Suicune, it seems. The only set in which CAP10 does not immediately beat Suicune with ThunderPunch is Crocune and CMShuffle (as Sleep Talk doesn't run CM). CroCune does little offensively to CAP10. If CAP10 switches in on a Calm Mind, the most Suicune can boost to is +2 before it has to Rest. Then, since CAP10 out-speeds it, it can actually 3HKO it before it wakes up. Offensive should only get in one Calm Mind before it attacks, which makes even HP Grass unable to OHKO. CAP10 out-speeds Suicune, remember. Volt Tackle is not necessary to beat Suicune, who is NOT a counter to CAP10 in any shape or form. Volt Tackle only makes killing Suicune faster, which may seem too powerful to some, but not to others.
Why Volt Tackle Might Be Broken:
Volt Tackle vs. WishBliss: 57.2% - 67.6% (2HKO)
Volt Tackle vs. Snorlax: 45.5% - 53.7% (2HKO after SR most of the time)
These two calculations are pretty much the only thing that makes Volt Tackle completely broken in the sense of damage output. These calculations mean CAP10 can deal with the walls switching into it just by using its STAB move, and not using its third or fourth move slot specifically for these threats. This really isn't wanted at all, seeing as though we want to make CAP10 "forced" to use its move pool to counter the specific threats it wants to counter. Quite frankly, giving it Volt Tackle kills all the Flying/Water types that ThunderPunch can, but also adds walls like Blissey and Snorlax, which is more or less eliminating into the necessity to use up a slot for a Fighting move.
While giving Trace CAP10 Volt Tackle seems like a great idea, remember that CAP10 can at the very least get Rest, if we don't give it any other recovery move in the Support move set thread. Does Trace CAP10 have the ability to abuse this combo, especially Rest Talk? This should be discussed.
To Fear My Shuckle, the entire second argument applies to Crabhammer as well, plus you can add in Tyranitar.
Hydro Pump: Just wanted to reiterate my TL;DR version of Hydro Pump's damage output, as many people seem to have not seen it: Hydro Pump only scores OHKO's on Weavile and Porygon-Z and 2HKO's on Machamp and Swampert that Surf cannot. The first two should be handled better by the Physical set anyway, and the latter two are not wanted, since Psychic and HP Grass are figured to be used. Surf does virtually the same damage output (OHKO's and 2HKO's) that Hydro Pump does. Hydro Pump's only positives will make it beat certain threats we do not want it to anyway. If you want the full skinny on Hydro Pump, check out my initial post and the Counters discussion thread. As to the "Water Gun" argument, that point is invalid, as it is important to discuss competitive-only moves at this time. Hydro Pump and Surf fit into that category. If a competitive move seems unnecessary, what purpose will it serve on CAP10? None. This is where our decision should lie.
The Dragon Moves: I'm just going by the facts on this one. Draco Meteor gives CAP10 its only way to deal with Kingdra without forcing another teammate to finish it off. Dragon Pulse does not. Not even Modest after SR damage. Giving CAP10 Dragon Pulse, doing 75% damage, and dying is not countering or "dealing with" Kingdra. Arguments including that another Pokemon can come in and finish off Kingdra are irrelevant, as CAP10 should deal with the threats it wants to handle on its own. We don't want Kingdra to go completely unchecked against CAP10 since it's a Dragon Dance user, something that CAP10 was originally designed to counter in the first place. Outrage is in the same boat as Draco Meteor (OHKO after SR), but I feel a -2 SpA drop is more dangerous than just letting CAP10 go two or three turns of a Max Attack Outrage, even if it's a Steel switch-in. Draco Meteor OR Outrage should be accepted, not both, with a precedence on Meteor.
Payback/Crunch/Dark Pulse: Normally, I would argue that Ice Punch hits for a 2HKO on Latias. However, Payback is extremely situational, only having to deal with Latias and Starmie, with Starmie being better handled by Electric attacks anyway. It also hits for a much more solid 2HKO on Latias, with even a really small chance of a OHKO after Rocks. This is pretty important, seeing as how Latias is such an important Offensive threat. Crunch, however, seems to be iffy. Payback is a better option for Latias, so she's out of the discussion. Rotom-A is better handled by the Special CAP10, scoring the same 2HKO's with Surf as Crunch. Giving both the Physical AND Special versions of CAP10 a way to deal with Rotom may be going overboard, but that's just my opinion. Crunch also does little to nothing against Dusknoir (4HKO after Leftovers), meaning Dusknoir will still kick the crap out of you with Pain Split + EQ. Cresselia is 5HKO'd after Leftovers. What is Crunch really doing beneficial then? Dark Pulse is in a similar boat as Crunch, however, it actually has a much better damage output. It's able to 3HKO Dusknoir (potential 2HKO if SR is down, and guaranteed with SR + 1 layer of Spikes), 4HKO Cresselia, and a better 2HKO on Standard Rotom-C. Not much better, but I feel Dark Pulse is actually a nice complement to Payback. Yes on Payback, weak yes on Dark Pulse, and no to Crunch.
Earth Power: It's too weak to hit some of the Pokemon Earthquake was intended to hit, like Jolteon, so I'll leave that out of my decision. Metagross (Lead) is 2HKO'd by Max Jolly Earthquake with SR over 75% of the time (most likely more, but I'm guesstimating here). I don't see the need there. Same with Jirachi, as this point will only be valid if people start running 252 Bold. Something also to consider: it OHKO's Lucario, something that no Special attack can do currently. Do we want Physical CAP10 AND Special CAP10 to be able to check Lucario? I'm not saying "no", but it's definitely something to think about. We need to discuss the benefits/negatives of this move further before any decision is made. So far, it seems superfluous considering EQ's presence.
Aqua Jet/Ice Shard: Here's the problem with these two moves. They aren't overpowered (except possibly in the case of Latias, preventing her from scoring two hits on CAP10), so that's not the issue. The issue is that with the way the move set is running right now, adding a Priority move to CAP10 might give it some sort of reasoning to be in the Lead position. Payback + Priority beats Azelf. Aero is 2HKO'd as well. In fact, CAP10 will pretty much beat all leads if it wanted to, except for Swampert and Machamp. Do we want CAP10 to go in this direction? I personally think not. I do not support these two moves for this very reason. Calling CAP10 a "lead counter" is a bit of a stretch as well, as it's not being used to beat certain Pokemon, but rather a wide range of Leads.