On second thoughts; Malamar was on a team that it fit on really well; it's probobly B-Tier. I've edited the post to reflect that.
Anyway; I have been speaking to other people who have played the game for their opinions on what they have used as well; giving me a much wider pool that I can write up, since a lot of them used pokemon I did not; or have not yet used personally. I also have a few more pokemon that I can add now; as well as ones I still haven't written up:
Chespin/Quilladin/Chesnaught: - D C Tier
Availability: Starter
Stats:
[Estimated]
Chespin: 56/61/65/48/45/38
Quilladin: 61/78/95/56/58/57
Chesnaught
: 88/107/122/74/75/64
Chesnaught is a very slow; physical tank; with passable special bulk.
Typing: Pure Grass is a pretty bad typing; and this is the typing that Chespin's first two forms have. Grass/Fighting is pretty redundant in terms of offense; as Fighting only hits Steel out of pokemon who resist grass; and it's pretty bad on the defense; while it removes the weakness to Bug; and adds a resistance to Dark; Fighting adds a Flying weakness [Now x4], Psychic weakness and Fairy weakness. Not really worth the trade-off; especially when you're already weak to Fire, Poison and Ice as well, giving Chesnaught
6 weaknesses; including one x4. That's not good when you're a tank.
Movepool:
Chesnaught's movepool gets quite a lot of coverage early; including Rollout in time for the first Gym; Bite; Pin Missile and eventually Mud Shot. However; while putting in all this coverage; Gamefreak apparently decided to forget to give a Grass/Fighting type a Fighting STAB until Lv 60; and this is Hammer Arm; which is less than ideal. Chesnaught gets a few other notable moves viva TM; such as Shadow Claw; Aerial Ace; Earthquake/Bulldoze; Dragon Claw; Rock Slide and Payback.
However; it is likely to be stuck with either Power-Up Punch or Rock Smash for Fighting STAB until Terminus Cave; and requireing to go into an optional area for a decent fighting STAB before Lv60 is far from ideal. Mercifully; it gets Grass STAB at an acceptable time; with Needle Arm at 26; and Seed Bomb at 35.
Spiky Shield is a pretty awful attack in general; and easily the worst signature move of the three.
Edit: I'm a moron and forgot TM Low Sweep in this run.
Major Battles:
Alexia - Can actually sweep the gym with Rollout, although some grinding may be required beforehand.
Grant - Poor; Amurua can OHKO with Take Down; while my Quilladin failed to even come close to a 2HKO with Vine Whip. Tyrunt easily overpowers it.
Korrina - Poor. Hawlucha rips Quilladin apart, Machoke overpowers it, and even Meinfoo is a slight danger if she burns Hypers on it. You have to beat Korrina's mons fast.
Ramos - If you for some reason have Pin Missile; you can beat Gogoat. Otherwise useless; outside of Return. STAB is resisted x4 by two mons and is an outright immunity to Gogoat.
Clemont - Average to Poor, two pokemon resist Grass. While it resists Electric, it's x4 weak to Flying; won't have a good Fighting STAB for Magneton [Although it may have Bulldoze] and Heliolisk can use normal-type attacks on it. Bulldoze can deal with Heliolist; but it will hardly be swift.
Edit: Low Sweep makes Chesnaught good here.
Valerie - Poor; weak to Fairy
Olympia - Poor; weak to Psychic
Wulfric - Poor; weak to Ice; and due to it's slow speed and physical nature; Cryongal will get an attack off before it moves; and Avullg is unlikely to be OHKO'ed.
Team Flare - Awful against the Poison and Fire types; strong against the Darks; although Houndooms are scary; as is Lysandre's Honchkrow. Can beat Mega Gyarados however, provided something else sponges Intimidate.
Rival - Beats Absol
Malva - Useless. Completely useless.
Wikstrom - Can deal with Probopass; but loses to everything else, as they have subtypes strong against Fighting.
Dransa - Can only fight Druggidon
Seibold - Has to be weary of Ice Beams. Gyarados can set up on it, especially with Intimidate. Crushes Barbunkle.
Diantha - OHKO'ed by Hawlucha
; can't hurt Goltergheist unless it's carrying Shadow Claw; and even then can lose; loses to Aurorus; loses to Tyrantum; loses to Goodra and completely annihilated by Mega Gardevoir. Chesnaught is
completely useless here.
Additional Comments: Chesnaught is awful in-game. It suffers from
horrible Gym matchups like Chikorita does; while it's a slow; physical attacker like Torterra; that lacks a good move at an acceptable time to make use of it's secondary typing [Unlike Torterra] In fact; I'd go as far to say that Chesnaught's gym matchups are actually
WORSE then Chikorita's. At least Chikorita is technically strong against Chuck due to Poliwrath. Chesnaught is strong against
no gyms; and only handles the first gym because it can set up Rollouts on the joke Surskit that doesn't even have a Bug move. Hammer Arm at 60 and having to go to an optional area for an even close to good Fighting STAB is just icing on the cake.
So is Venusaur existing, who arguably does physical just as well with a higher BP STAB, Mega Evolution and status moves; and the fact you're giving up Froakie and Delphox for this. Opportunity Cost.
Note Chesnaught being slow also hampers it in terms of efficiency, since the enemy often goes first, leading to more animations, more damage taken, and thus more healing needed.
Being able to Bulk Up is nice; but with 6 weaknesses; it's not getting much chance.
For the 6th generation [And 2 remakes] in a row; the Grass starter is the worst one to pick for in-game purposes. It's like the bad parts of Chikorita mixed with the downsides of Torterra, without the redeeming qualities of either [Utility/Status and actually having GOOD MOVES at a reasonable time]. I lothed using this thing, and the only thing that kept me from boxing it outright was to try and get some use from it.
If Chesnaught didn't have such a good TM movepool and coverage it would been lower. I'm talking putting it in E if it had Serperior's coverage. At least Serperior was fast.
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I had Froakie typed up but then my browser crashed and I didn't save it; so I'll do that later.
However, I will give some nominations for the F-Tier that shouldn't need much elaboration:
Spinda - Tier F
This thing comes on Route 21. That's after WULFRIC. And it's USELESS.
Carbink - Tier F
Bad offensive movepool? Check. Rare? Check. Base 50 in both offense? Check.
Chingling - Tier F/E
Chimecho sucks. Chingling is worse. It's a time-dependant happiness evolution; yet comes far later than the other happiness evolution babies in the game; such as Budew, Rilou and Azurill. Oh; and you can pick up Mr.Mime or Dwebble here instead. Maybe E because Chimecho isn't COMPLETELY useless.