Known in the main Pokemon series and in Pokemon GO for its massive HP stats, Chansey is an incredibly tanky Pokemon that can outlast its opponents in battles of attrition.
Though it is seldom used in PvE environments, Chansey can be an effective gym defender due to its massive health, drawing out battles and wearing down its Pokemon GO opponents. Its attack and defensive stats pale in comparison to the HP it retains, but players using Chansey will still want to optimize the Pokemon's moveset for optimal damage just to make sure they're getting the best out of their tanky Normal-type.
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Pokemon GO: Optimizing Chansey's moveset by taking advantage of its Charge Moves
Unfortunately for Chansey, the Egg Pokemon doesn't have a particularly stellar collection of moves. It possesses two of the less-desirable Fast Moves in the game with Pound and Zen Headbutt. Chansey does have more variety in its Charge Moves with Dazzling Gleam, Hyper Beam, Psybeam, and Psychic, so the clear-cut plan for trainers should be gearing this Pokemon up to utilize its Charge Moves as best as possible due to the fact it is likely to be in the fight for a while unless it is being directly countered.
For optimal use, specifically in PvP situations such as gym defense (its moves' stats were nerfed in Battle League), trainers may want to give the combination of Pound, Dazzling Gleam, and Hyper Beam a shot. Pound and Zen Headbutt are both admittedly difficult to work with, but Pound at least receives the Same Type Attack Bonus (STAB) in damage due to matching types with Chansey. Dazzling Gleam costs the same as Psychic, but deals super effective damage against Fighting-type Pokemon that heavily counter Chansey. Hyper Beam also receives STAB, and hits considerably hard despite being one of Pokemon GO's slowest-charging moves.
Chansey is best served in Pokemon GO PvP defending gyms and buying time for trainers protecting the gym to place more Pokemon in the gym or to buff up those that are already inside. The Egg Pokemon's stats were sadly nerfed in Pokemon GO's Battle League to a significant degree, so it has many hurdles to overcome in order to perform well. Many players have passed Chansey over in favor of its evolution Blissey for optimal PvP performance in multiple facets, but Chansey is still capable of doing the job when it comes to defense.
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