Moves
Spikes gives Chesnaught and its teammates a way to directly punish switches and weaken the opposing team over the course of the game. Wood Hammer allows Chesnaught to hit Water-types such as Slowbro and Primarina and Ground-types like Swampert and Hippowdon. Roar helps mitigate some of Chesnaught's passiveness that makes it setup fodder for Swords Dance Scizor and Heracross by phazing them. This also works well in tandem with Spikes damage. Drain Punch gives Chesnaught a form of recovery while damaging Dark- and Steel-types like Bisharp and Cobalion. Leech Seed can be run instead to generate passive recovery for Chesnaught so it isn't overreliant on Synthesis, which greatly benefits Rocky Helmet sets particularly. Toxic can be run to punish Chesnaught's switch-ins such as Latias, Moltres, and Infernape to weaken them over time and prevent setup sweepers like Dragon Dance Mega Altaria from setting up.
Set Details
12 Speed EVs enable Chesnaught to outspeed Alomomola and potentially KO it with Wood Hammer if it's sufficiently weakened. Leftovers provides consistent passive recovery that can help it check threats like Krookodile without being forced to rely on recovery, while Rocky Helmet helps rack up more chip damage, aided by Spikes damage, on physical foes such as Choice Band Scizor that try to attack it or pivot out with U-turn.
Usage Tips
Chesnaught can be switched into physical attackers that fail to substantially damage it, such as Bisharp, Krookodile, and Crawdaunt, to generate free turns as they're forced out. Chesnaught can take advantage of free turns to either heal itself or set up Spikes, which can punish the switches that Chesnaught forces by virtue of its typing and physical bulk. Synthesis should be used to maintain Chesnaught's HP if it's needed to check a threatening physical attacker such as Crawdaunt and Zeraora, but it has low PP, so being aware of this and preserving it for when it's necessary ensures Chesnaught has the best matchup against key physical wallbreakers. Chesnaught should utilize Drain Punch consistently due to its good neutral coverage against foes it switches into like Zeraora. It is also optimal to use it against foes such as Krookodile and Crawdaunt to prevent Chesnaught from being worn down through recoil if it can be avoided. Chesnaught is extremely passive and does not have much offensive presence, so it should be wary of letting setup sweepers in. However, if it is running Roar, it can phaze them. Roar can also be used to phaze entry hazard removers predicted to switch in, such as Moltres, Rotom-H, and Tentacruel, to prevent them from being able to remove Chesnaught's Spikes and force them to take more damage from entry hazards when switching back in. Leech Seed should also be used liberally if being run; Leech Seed and Leftovers recovery can help to keep Chesnaught healthy without being forced to rely on Synthesis as much. If a foe is predicted to switch out, using Leech Seed consistently helps to wear switch-ins down and punish them. Status can burden Chesnaught greatly, particularly Toxic poison and burn, so being wary of potential Toxic users like Alomomola and Blissey and Scald users such as Suicune and Empoleon can keep Chesnaught clear of status. Without cleric support, switching Chesnaught into these Pokemon, despite its typing and resistances, can cripple it for the remainder of the game.
Team Options
Chesnaught fits best on bulky offense and balance teams that need a physically defensive Pokemon with a good matchup against several of the tier's most threatening Dark-types. It appreciates Flying-type checks such as Rotom-H, Nihilego, and Diancie greatly, as they can pivot into foes like Moltres and Togekiss that Chesnaught is forced out by and appreciate Chesnaught dealing with more specially defensive foes such as Blissey. Stealth Rock support from teammates such as the aforementioned Nihilego and Diancie as well as other options such as Hippowdon, Mega Steelix, and Mega Aggron helps Chesnaught by stacking residual damage with Spikes and further punishing switches. The latter two options as well as other Steel-types such as Scizor can help Chesnaught in the matchup against Fairy- and Psychic-types such as Mega Altaria and Latias too. Bulky Water-types such as Slowbro, Tentacruel, and Empoleon can take care of threatening Fire-types such as Infernape and Volcanion for Chesnaught and appreciate its ability to switch into several physical attackers such as Crawdaunt that these Pokemon struggle with. Due to Chesnaught's susceptibility to status, cleric support from teammates such as Togekiss, Blissey, and Florges is appreciated, allowing it to switch into Scald and Toxic more freely to check certain Water-types or set up Spikes. The latter two can also provide Wish support to make Chesnaught less reliant on Synthesis. Immediate offensive threats such as Latias, Choice Band Crawdaunt, and Nidoking can help to make up for Chesnaught's overall passivity, preventing it from letting in too many opposing threats or giving bulkier foes more opportunities to recover HP. Chesnaught offers these Pokemon Spikes support for chip damage on foes as a result; Bisharp is an especially good teammate, providing offensive presence, being able to deter Defog with Defiant, and taking advantage of Spikes support immensely. Due to Chesnaught's role as a Spikes setter, having other team options that can punish opposing entry hazard removal, such as Taunt Hydreigon, Electrium Z Latias, and Pursuit Mega Aerodactyl, is extremely useful.