Overview
Leads play an important role in the first few turns of a battle. Whether its laying out the hazards to threatening other leads to setting up Dual Screens, all matches are partially determined on how well the lead does its job. Many times, frail and powerful sweepers such as Houndoom and Darmanitan are able to pull off a successful sweep, due to hazards slicing into the opponents HP or protection from Reflect and/or Light Screen. Stall teams rely heavily on hazards, since they force the opponent to switch out while they lose residual damage. There are also leads that prevent other leads from supporting their teammates. These leads are just as good, as long as they have backup, like Ambipom and Bronzong. The leads that are explained below this paragraph are either anti-leads, support leads, and miscellaneous.
Anti-Leads
The sole purpose of these leads are to threaten other leads from setting up hazards or screens. Some also carry support moves of their own and some are usually suicidal, which also means they would have a Focus Sash. The combo Anti-Lead+Defensive Supporting Backup Lead works extremely well.
Pure Offensive Anti-Leads
Arcanine, Chandelure, Machamp, Nidoking, Porygon-Z, Sharpedo, Weavile.
Attack Range (4):110-130
Special Attack Range (3):≈125-145
Speed Range (7):55-125
HP Range (7):60-90
Defense Range (7):40-90
Special Defense Range (7):40-90
BST Range (7):460-555
Summary
The definition of these Pokémon would be sheer power. They can 2HKO anything that doesn't resist it. Some of them, such as Sharpedo and Weavile, are very fast and frail, while others like Chandelure and Machamp are slow and rather bulky. The only drawback to them is that they don't have U-turn or Volt Switch, which makes their attacks predictable. Around half of them would appreciate a choice item, except for Machamp, Weavile, and Arcanine, who would rather have Leftovers or a Life Orb. Also, Weavile can setup using Swords Dance, which can provide a potential sweep. Others can use Substitute on a Pokémon they resist, although early sweeps tend to fail.
Offensive Scouters
Accelgor, Ambipom, Archeops, Azelf, Darmanitan, Flygon, Mienshao, Rotom-H, Victini, Yanmega, Zoroark.
Attack Range (6):100-140
Special Attack Range (6):100-125
HP Range (10):50-105
Speed Range (10):86-145
Defense Range (10):55-107
Special Defense Range (10):55-107
BST Range (10): 480-600
Summary
Even though they are scouters, some of them are just has powerful has Chandelure or Machamp. Darmanitan is the equivalency of an 18 wheeler truck, and Archeops is identical to a diamond-tipped drill. Accelgor is faster than the fastest ninjas, and Yanmega is even faster if it has Speed Boost as an ability. Azelf and Yanmega really deserves a special mention. Azelf can also use a support move or Taunt if it wants to, and Specs Tinted Lens Yanmega can pulverize anything but the best of walls, since nothing resists it.
Non-Offensive or Semi-Offensive Anti-Leads
Crobat, Sableye
Summary
Sableye is very interesting for a lead. Even without any moves, it can be the best of all Anti-Leads, due to its Prankster ability. It can use Toxic, Trick, Will-o-wisp, Taunt, you name it. Crobat's most valuable asset is its whooping 130 speed, which is only outsped by the rare Ninjask, Electrode, 71 base speed and above scarfers, and the uncommon Aceelgor. It can also use Taunt and can also scout.
Support Leads
Support Leads are subdivided into two more groups: the fast and the slow. Fast leads are generally faster then most Pokémon (which is obvious), so they are guaranteed to setup whatever they have before they faint. Some of them are given sashes, and other can actually take several neutral hits, like Cobalion and Roserade. Slow leads are usually support walls, and can endure many neutral hits.
Fast Support Leads
Accelgor, Azelf, Cobalion, Froslass, Roserade, Scolipede.
Speed Range (6):90-145
Attack Range (4):80-125
Special Attack Range (5):80-125
HP Range (6):60-91
Defense (6):40-129
Special Defense (6):60-105
BST Range (6):475-580
Summary
If I were these Pokémon, it would be hell. 4 out of 6 of them are Spikers and most of them are suicide leads. Only Cobalion and Roserade can be also physical and special walls at the same time. The 4 suiciders are all very quick, frail, and should be equipped with a Focus Sash. If your opponent has Rapid Spin, then your lead would be rather useless.
Defensive Support Leads
Bronzong, Claydol, Empoleon, Gligar, Registeel, Swampert
HP Range (6):60-100
Defense (6):88-150
Special Defense (6):65-150
Attack Range (4):70-110
Special Attack Range (3):70-111
Speed Range (6):33-85
BST (6):430-580
Summary
Look at the defenses of Eviolite Gligar and Registeel: its defenses are almost as high as Eviolite Dusclops. Gligar's physical defense is almost as high as Shuckle too. They can certainly be both supporting Pokémon and walls to threats. Its also funny that 3 of the 6 are former OU Pokémon. All of them make great leads, and I'll especially support Bronzong and Swampert.
Miscellaneous
Xatu.
Summary
This Pokémon is a mixed bag of goodies. Its defenses are horrible for even a tank;it even has less bulk than Azelf. However, it's ability makes it an even bigger asset than Crobat's speed and Dragonite's Multiscale, Magic Bounce. As long as this Pokémon is on the field, entry hazards, phazing moves, status moves, and pseudo status moves will bounce back. This Pokemon will counter all of Sableye's non-direct moves. However, just make sure that Pursuit trappers don't come in and the situation would be a lot easier to deal with. I guess this psychic bird could be a Anti-Lead, but Pokémon such as Arcanine would just this bird down with a Wild Charge, making Arcanine a Anti-Anti-Lead, which is confusing.
Leads play an important role in the first few turns of a battle. Whether its laying out the hazards to threatening other leads to setting up Dual Screens, all matches are partially determined on how well the lead does its job. Many times, frail and powerful sweepers such as Houndoom and Darmanitan are able to pull off a successful sweep, due to hazards slicing into the opponents HP or protection from Reflect and/or Light Screen. Stall teams rely heavily on hazards, since they force the opponent to switch out while they lose residual damage. There are also leads that prevent other leads from supporting their teammates. These leads are just as good, as long as they have backup, like Ambipom and Bronzong. The leads that are explained below this paragraph are either anti-leads, support leads, and miscellaneous.
Anti-Leads
The sole purpose of these leads are to threaten other leads from setting up hazards or screens. Some also carry support moves of their own and some are usually suicidal, which also means they would have a Focus Sash. The combo Anti-Lead+Defensive Supporting Backup Lead works extremely well.
Pure Offensive Anti-Leads







Arcanine, Chandelure, Machamp, Nidoking, Porygon-Z, Sharpedo, Weavile.
Attack Range (4):110-130
Special Attack Range (3):≈125-145
Speed Range (7):55-125
HP Range (7):60-90
Defense Range (7):40-90
Special Defense Range (7):40-90
BST Range (7):460-555
Summary
The definition of these Pokémon would be sheer power. They can 2HKO anything that doesn't resist it. Some of them, such as Sharpedo and Weavile, are very fast and frail, while others like Chandelure and Machamp are slow and rather bulky. The only drawback to them is that they don't have U-turn or Volt Switch, which makes their attacks predictable. Around half of them would appreciate a choice item, except for Machamp, Weavile, and Arcanine, who would rather have Leftovers or a Life Orb. Also, Weavile can setup using Swords Dance, which can provide a potential sweep. Others can use Substitute on a Pokémon they resist, although early sweeps tend to fail.
Offensive Scouters











Accelgor, Ambipom, Archeops, Azelf, Darmanitan, Flygon, Mienshao, Rotom-H, Victini, Yanmega, Zoroark.
Attack Range (6):100-140
Special Attack Range (6):100-125
HP Range (10):50-105
Speed Range (10):86-145
Defense Range (10):55-107
Special Defense Range (10):55-107
BST Range (10): 480-600
Summary
Even though they are scouters, some of them are just has powerful has Chandelure or Machamp. Darmanitan is the equivalency of an 18 wheeler truck, and Archeops is identical to a diamond-tipped drill. Accelgor is faster than the fastest ninjas, and Yanmega is even faster if it has Speed Boost as an ability. Azelf and Yanmega really deserves a special mention. Azelf can also use a support move or Taunt if it wants to, and Specs Tinted Lens Yanmega can pulverize anything but the best of walls, since nothing resists it.
Non-Offensive or Semi-Offensive Anti-Leads


Crobat, Sableye
Summary
Sableye is very interesting for a lead. Even without any moves, it can be the best of all Anti-Leads, due to its Prankster ability. It can use Toxic, Trick, Will-o-wisp, Taunt, you name it. Crobat's most valuable asset is its whooping 130 speed, which is only outsped by the rare Ninjask, Electrode, 71 base speed and above scarfers, and the uncommon Aceelgor. It can also use Taunt and can also scout.
Support Leads
Support Leads are subdivided into two more groups: the fast and the slow. Fast leads are generally faster then most Pokémon (which is obvious), so they are guaranteed to setup whatever they have before they faint. Some of them are given sashes, and other can actually take several neutral hits, like Cobalion and Roserade. Slow leads are usually support walls, and can endure many neutral hits.
Fast Support Leads






Accelgor, Azelf, Cobalion, Froslass, Roserade, Scolipede.
Speed Range (6):90-145
Attack Range (4):80-125
Special Attack Range (5):80-125
HP Range (6):60-91
Defense (6):40-129
Special Defense (6):60-105
BST Range (6):475-580
Summary
If I were these Pokémon, it would be hell. 4 out of 6 of them are Spikers and most of them are suicide leads. Only Cobalion and Roserade can be also physical and special walls at the same time. The 4 suiciders are all very quick, frail, and should be equipped with a Focus Sash. If your opponent has Rapid Spin, then your lead would be rather useless.
Defensive Support Leads






Bronzong, Claydol, Empoleon, Gligar, Registeel, Swampert
HP Range (6):60-100
Defense (6):88-150
Special Defense (6):65-150
Attack Range (4):70-110
Special Attack Range (3):70-111
Speed Range (6):33-85
BST (6):430-580
Summary
Look at the defenses of Eviolite Gligar and Registeel: its defenses are almost as high as Eviolite Dusclops. Gligar's physical defense is almost as high as Shuckle too. They can certainly be both supporting Pokémon and walls to threats. Its also funny that 3 of the 6 are former OU Pokémon. All of them make great leads, and I'll especially support Bronzong and Swampert.
Miscellaneous

Xatu.
Summary
This Pokémon is a mixed bag of goodies. Its defenses are horrible for even a tank;it even has less bulk than Azelf. However, it's ability makes it an even bigger asset than Crobat's speed and Dragonite's Multiscale, Magic Bounce. As long as this Pokémon is on the field, entry hazards, phazing moves, status moves, and pseudo status moves will bounce back. This Pokemon will counter all of Sableye's non-direct moves. However, just make sure that Pursuit trappers don't come in and the situation would be a lot easier to deal with. I guess this psychic bird could be a Anti-Lead, but Pokémon such as Arcanine would just this bird down with a Wild Charge, making Arcanine a Anti-Anti-Lead, which is confusing.