My defender tier list
Considering damage output before being killed, time necessary to defeat and gym placement
I havent done enough gym battle since gen2 so that's just a estimation
I consider pokemon with max CP under 2800 as unusable. They were hardly usable before g2 and now there are even more defender with higher CP.
Tier 1
Blissey without Psychic
Tier 1,5
Blissey with Psychic
Tier 2
Snorlax with ZH
Tier 2,5
Dragonite with Outrage
Snorlax with Lick
Tier 3
Tyranitar (crunch)
Vaporeon
Exeggutor with Confusion
Tier 3,5
Rhydon
Tier 4
Gyarados with DT
Golem
Lapras (such low CP)
Machamp with DP
Edit : I moved up vaporeon, Dragonite and Lick Snorlax
Answers
Interesting and makes sense (but Rhydon should be below Vap with his double weakness to one of the strongest mons, Vap :) ).
What lacks in there is a position for tough defenders with lower cp (slowbro and king, maybe still poliwarth, others from gen 2). Or do you consider theiy are no more good defenders due to dark types maybe?
What about Espeon and even Flareon as high CP mon? Are they weaker than Machamp or Golem?
You are right with stamina indeed. Also with base stats distribution but not due to their sum but due to their product. And given golem ones are more balanced, product is higher, so golem is better, as you mentioned.
100 + 100 = 200
1+ 199 = 200
100100=10000
1199 = 199
Above is an extreame example to show why we need to multiply the stats instead of sum them. In damage formula they work with multiplication and duvision, not with sumation and differences :).
Pure defensive (amount of damage a pkm can take) is sta x def:
Exeggutor: 158 x 190 = 30.020
Espeon: 194 x 130 = 25.200
The difference is noticable, but not huge.
It is easyer to get a type advantage against exeggutor than Espeon. Espeon hits way harder.
Combination of these facts makes Espeon as good at Exeggutor least imo.
Why would Steelix be way better than Golem. Similar total of base stats (only 3% more for steelix)
Defense is more important on defenders (look to blissey), but underestimated by CP via square rooting. Pure Defense on
Golem: 229 x 160 = 33640
Steelix: 333 x 150 = 49950
Both Double disavantage vs Water (double weak/unresisted vs Weak/resisted)
This does not apply for all moves. Earthquake on Steelix hits water for normal damage.
Golem always takes double super effective damage.
500 CP lower
Yes, underestimated by CP-Calculation, i said already. But still a better defender imo.
The combination of better defense and better resistance against water will roughly double (Factor 1,9) time until it faints against the same water attacker.
During this time, it deals a bit more damage than golem:
Steelix: 148 * 333 * 150 * 0,8 (being hit super effective) * 0,9 (hitting not super effective or non SAB with quick move) = 5.323.000
Golem: 211 * 229 * 160 * 0,8² = 4.949.000
This is a great thoughtful list. Thank you for putting it together. The main changes to the gym meta is to slow down the spamming attacks, which makes weaknesses a bit harder to exploit.
My list
Tier 1
We can all agree that Blissey and Snorlax are at the top. Although, for me, Snorlax with Lick belongs much lower. Let's not confuse "high CP" with "hard to fight against". Snorlax with Lick is really easy to beat.
Tier 2
Then I would put Vaporeon (high HP, CP, strong moves and single weakness to grass).
Tier 2.5
Then there is a tier of "Strong mons with exploitable weaknesses" - Dragonite, Rhydon, Gyarados, Exeggutor, Tyrannitar.
Tier 3
Then there is Lapras because of low CP
Tier 4
Then there is "the rest" - wouldn't be my top choice mons but offer good variety - Golem, Poliwrath, Venusaur, Jolteon, Flareon, Arcanine, Psychic with Confusion, etc.
Part of me feels like this list looks a lot like the prior list, minus the nerfs and + Blissey and Tyrranitar... Hopefully as we play the gym meta more we'll discover more subtlety that will make more defenders relevant. If not, then the gym game will stay stale.