The "big 19" basic explanation – Snorlax (week: 11-2) – A tough defender
Since the STAB multiplier has decreased, beating Snorlaxes is even harder with generalists like Vaporeon.
Body Slam Snorlaxes?
Body Slam is the best charge move for Snorlax at defense, is hard to dodge and comes very frequently.
To beat a BS Snorlax, you may need 2–3 attackers, depend on the pokémon levels.
Gengar will be a good option, taking 49% less damage, but Tyranitar will be the best with enough HP while resisting BS. Magneton/Scizor/Forretress won't last very long, making them bad generalists. The downside for Gengar is that it takes super effective damage from all Snorlax's quick moves, making it more like a glass cannon specialist.
1 Tyranitar is enough to kill a BS Snorlax with dodging. However, it outputs less damage than before. But it also takes slightly less damage.
The anniversary event is very disappointing, no need to mention again.