Claydol, once one of the most prominent support Pokemon around, now lies overshadowed by many of the newer faces and older rivals that it has only a few advantages over. Bronzong, with a superior defensive typing and slightly higher stats, is more popular as a supporter, and Claydol's only advantages from a support point of view are its much higher Speed, which allows it to outpace most Scizor and some Tyranitar, as well as its access to Rapid Spin. Even in the spinning department, however, it is overshadowed by Forretress, who has a superior defensive typing, an equally good support movepool, and the ability to take out spinblocking Ghost-types. Claydol's many weaknesses to common attacking types do not help its case either. However, Claydol's balanced offensive and defensive stats as well as its Ground-type STAB still make it worth using in certain situations.
Rapid Spin is the most important move on the set, as it removes entry hazards that can be crippling for the rest of the Pokemon on your team; vice versa, Claydol can also cut opponents' lifespans short with its own Stealth Rock. Attacking moves are recommended in the last two slots as many OU Pokemon can cause Claydol trouble. The first of these should be a Ground-type STAB move, as Ground is an excellent attacking type and helps Claydol greatly against common Steel-types. Earthquake is usually the superior choice as it has a chance to OHKO Lucario and Infernape, as well as 2HKO Tyranitar and Jirachi, which Earth Power cannot do. However, Earth Power provides a guaranteed 2HKO on standard Choice Band Metagross, is not affected by Intimidate, and prevents the need for splitting EVs if you wish to run Ice Beam.
There are a number of viable options in the last slot, but it is generally best to avoid splitting EVs as this reduces Claydol's already low offensive power. Thus, if using Earth Power, go for Ice Beam, and if running Earthquake, use Explosion. In general, Ice Beam is the best coverage option as it gives Claydol super effective coverage on not only the Grass- and Flying-types that resist or are immune to Ground, but also Dragon-types such as Dragonite and Flygon. However, it lacks power against foes it hits for neutral damage, such as Rotom-A. On the physical side, the option that most merits a mention is Explosion. This might seem ridiculous considering the fact that your opponent's first switch-in to Claydol is usually a Ghost-type, but it is by far Claydol's best way to deal significant damage. Explosion can create an important gap in the opponent's team, especially if it hits a bulky Water- or Grass-type, and also grants a free switch that could give you the opportunity to set up a sweep or regain momentum.Team Options & Additional Comments >>>
Claydol has a whole host of other support options that can easily replace Rapid Spin or Stealth Rock, and can hence be specialized for different teams. Chief among these are Reflect and Light Screen, which have great merit on offensive teams that rely heavily on setup sweepers. As Claydol also learns Stealth Rock, it can mimic pure support Uxie in this way, by using Stealth Rock alongside dual screens with Explosion in place of Memento. Claydol can set up Gravity as well; although it is slightly overshadowed by Bronzong and Forretress in this role, it can make use of Gravity with a perfectly accurate Stone Edge, and unlike Bronzong, it isn't weak to Ground-type attacks under Gravity. Alternatively, Claydol learns Trick Room too. Lastly, Trick can be used alongside a Choice item to hopefully cripple an incoming wall or counter.
Shadow Ball is another decent option that allows Claydol to hit spinblocking Ghost-types; this is particularly important as two of the three OU Ghost-types, namely Rotom-A and Gengar, are immune to Earth Power by virtue of their Levitate ability. Toxic is a very interesting option as it can cripple bulky Water-types, such as Swampert and Vaporeon, who are common switch-ins to Claydol. Grass Knot always 2HKOes 252/0 Swampert through Leftovers, but it deals pitiful damage to Suicune and Vaporeon.
Checks and Counters
Bulky Water-types are perhaps the best counters to Claydol. Gyarados is probably the best choice as it is immune to Earthquake, takes little from Ice Beam, and can easily set up with Dragon Dance or use Taunt to stop Claydol from using its support moves. The same is more or less true for Suicune and Vaporeon, who both dislike Toxic but have strong Water-type STAB moves that will KO Claydol. Starmie has no such problem as Natural Cure heals it of poison; it also has access to Recover to offset any damage that Claydol can do. Swampert does worse, as it is 2HKOed by the rare Grass Knot and dislikes Toxic, but it can threaten Claydol in much the same fashion. Lastly, while most Dragon-types cannot take Ice Beam, Kingdra is neutral to Ice-type attacks and can take almost anything Claydol throws at it while destroying Claydol with its Water-type STAB moves or setting up with Dragon Dance.
Ghost-types are an issue for Claydol. The common Gengar and Rotom-A are both immune to Earthquake thanks to Levitate and can defeat Claydol with their STAB moves. However, Gengar cannot switch into Shadow Ball or Psychic twice, while defensive Rotom-A dislikes Toxic. Dusknoir is an issue too, but does not have any strong Ghost-type STAB attacks nor an immunity to Ground-type moves. Bug- and Dark-types are problematic for Claydol, especially as the users of these moves, namely Scizor and Tyranitar, tend to have access to Pursuit as well. Scizor can take anything Claydol throws its way barring Hidden Power Fire, and, in addition to Pursuit, can use U-turn too, which KOes Claydol if it stays in and allows Scizor to scout the incoming Pokemon if Claydol switches. Tyranitar is much the same, but it has a more powerful STAB Pursuit and can also use STAB Crunch against Claydol that stay in. Heracross is noteworthy for its powerful STAB Megahorn, ability to absorb Toxic for a Guts boost, and access to Pursuit. Furthermore, it is the only one of the above that resists Earth Power, but conversely, it is weak to Psychic. Grass-types can be a nuisance as well. The biggest problem of the bunch is Celebi, who resists both of Claydol's STAB moves, doesn't take much damage from Ice Beam and Shadow Ball, and can hit Claydol hard with Grass Knot. Breloom does well too, despite weaknesses to Psychic and Ice Beam, and can use Spore or Seed Bomb to defeat Claydol. Roserade lacks the Ground-type resistance of its peers and is weak to Ice Beam and Psychic as well, but has a high Special Defense stat to shrug off super effective attacks, along with access to STAB Grass Knot and Leaf Storm.
Lastly, Bronzong and Skarmory can take just about anything from Claydol, but they cannot immediately pose a threat. Bronzong must have Grass Knot to cause any real damage, and can only really hurt Claydol by putting it to sleep with Hypnosis. Skarmory can whittle it down with Brave Bird, but it must be wary of being caught by Earth Power when it uses Roost against a slower Claydol. Blissey can take any special hit and is not terribly bothered by most of Claydol's physical attacks, but it should be mindful of Explosion.