is first not because "lol crit memes", but for one critical reason, he's the de-facto only universal revenge killer in the tier, one that can apply damage to everything that dares to switch in. There some candidates for the role but no one can do that against every team. Zapdos is stopped by Rhydon+Jolteon/Dodrio by Rhydon/Persian by Gengar/Snorlax is too slow to apply pressure vs unparad Chansey. In short Tauros holds a niche that no one can take, you wouldn't even be able to use sleep properly without him pressuring the slept mon after.
aside from Tauros is the only pokemon i would never drop on any team, even for fun purposes, that's what grants him the S+ in my eyes. I don't need to tell why he is so strong, with a lot of possibilities for the 4 moveslots. He wouldn't be THAT broken without Chansey to burn sleep on though, but we do need Chansey for the special barrage.
vs
The star climbed the food chain pretty well lately, with teams being more and more hostile toward Zapdos, deserving the S- to me and the status of big 5. I still can't rank Exeggutor lower though, the combination of Psychic type+Explosion (backed up by amazing stats) is just too much, it allows to choose and safely explode any target. To this add that it is the only Rhydon check in the tier, and there it is the undisputed number 4. (I refuse to hear any comment about Starmie being a Rhydon check, if your Starmie possess the ability Limber, i don't care, mine never did).
was always the worse of the two Recover leads to me, the weak link of the chain, and i still think it, but spamming Starmie only would never be good, Mega Drain Eggy would destroy you. Even if it is flawed being able to fill the lead role as well as he does is plenty of accomplishment already. But the real deal with him is the rise of Eggyless teams, without his biggest enemy around back Zam gained a lot of power and popularity.
is my biggest gripe, if anyone spoke with me prior to last spl, he would know Zapdos was always the real missing big 5 to me, not Starmie. His stats are all around disgusting, leaving little to be desired, i'd even go as far as saying that without Jolteon or Rhydon, Zapdos is a hair better than Tauros itself. Why though? First, i always found harder to switch on Zapdos, Tauros might have the best coverage, but it is spreaded through 4 moveslots, all of them needed, Body Slam, Hyper Beam when something isn't in range of anything else, Blizzard which is easily taken by waters, and Earthquake for Gengar/Rhydon. Zapdos' reply is a big fuck you to that: Thunderbolt neutral on most cases, destroyer of waters, and Drill Peck to fuck up Chansey+Exeggutor, good luck pivoting between two moves, the other two being Thunder Wave and Agility. So what happened? Simply speaking dropping Exeggutor makes your team weaker to Alakazam but allows space for Jolteon/Rhydon where there wasn't prior. It is the same concept of SS Dracovish being so much strong and unfair, but the tier itself just naturally countered it, so people shy away from running it, as it would be dead weight vs most teams. I believe Zapdos could make his return again if back Zam punishes the Water+Jolteon builds. As it is today sadly Zapdos, one of the biggest tyrants of old rby is in decline.
holds a special place in my heart, i would always choose him in spite of every big 4 team they could throw at me, because to me it had the easier "bad mu" in the triangle. Zapdos vs Rhydon was atrocious to play, but water vs Zapdos wasn't any better. Rhydon vs water on the other hand while not good it wasn't as oppressing to me, so i naturally became the biggest Rhydon guy, icing on the cake Stoss Chansey becoming the big thing from 2015 made Rhydon basicly never useless, unless used poorly. It was my boy. Sadly everything i love seems to be trashed in current meta, Sing Chansey become ultra spammed, and when it wasn't sing it was Counter (both of them carry Ice Beam). It became harder and harder to make use of him, but regardless it stays on a certain level. His physical pressure is immense.
is a particular case, i always despised her existence. Being the only Psychic leads which doesn't sleep block at all, just to ice spam a little early. However everything changed when Sing Chansey gained popularity, Jynx become really appealing to me, blocking completely any mono Ice Beam Chansey.
is an oddball, it used to be the greatest Reflect Lax counter, but the return of Hyper Beam greatly damaged his role, it stays a great mon regardless, as anything packing Explosion in the moveset though.
is another weird case for sure, everyone became fangirl of him for his niche of walling EQless Lax seemly forever. Not realizing that in return Gengar did nothing noteworthy to pressure Chansey, which often forced boom allowing Lax to rampage as nothing happened. Gengar will always be mediocre at best to me.
and
are criminally underated, what the fuck guys? Sure they come with risks but the they don't deserve to be ignored this much, especially the fire warrior. Their match ups vs Tauros and Snorlax should speak miles of their viability, the only two mons in the tier to outright 2hko Tauros without killing themself in the process.
has fallen back to where he belongs again, the droppage of Exeggutor sealed his doom, teams got faster packing faster psychics.
EVERYTHING that could go wrong for Lapras, just did. Sing Chansey sleeping early took away a BIG chunk of Lapras popularity, being the backup sleeper, and the finishing blow was dealt by Exeggutor (one of his slower preys) left on the bench more often leaving space for harder things to deal with for Lapras. That said Cloyster got popular so lapras isn't awful today, but it won't shine was much as it used to do.
once used to be Rhydon's league, because Chansey knew only one moveset (Thunderbolt, Ice Beam, Soft Boiled, Thunder Wave), so there wasn't big gap in terms of utility. Golem was there to try his luck finding Zapdos, while also having the luxury of exploding if you discovered that the mu didn't go according to plan. With Reflect era Golem collapsed completely, Rhydon had a 101+ hps sub to make full use of his opponent's strenght, and Snorlax running Reflect didn't help either, at least Rhydon can 3hko a sleeping Lax before reflect (double switch on Rest). Despite packing a respectable 110 attack stat (yes in rby it's 110, will turn into 120 from gsc) Golem falls short on killing full Starmie with Explosion too, giving no reason not to run Cloyster in his place.