• R/B
• G/S
• R/S
• D/P
• Strategy
• Moves

Ninetales

Flash Fire Grants immunity to Fire and increases Fire's power 50% when hit by a Fire move.

When used with some prediction, Ninetales can screw around with his opponents badly. You have 100 Special Defense, so your opponent will most likely bring in a physical attacker to mess with you—only to get burned by Will-O-Wisp. When the end is near and you want to sacrifice Ninetales, it's time for his big contribution to the team: Grudge. If you use it on the turn your opponent kills you, all PP of that attacking move is stripped off. This can help you to set up another Pokémon. For example, a Donphan without Earthquake is not going to stop a Dragon Dancing Tyranitar.

Other Options

You can use Flamethrower over Fire Blast, but Fire Blast is recommended because its Special Attack is quite low. Confuse Ray makes you hard to hit, but can work against you when you Grudge and they hit themselves in Confusion. Hypnosis is a gamble, but a very rewarding one. You can use it with Will-O-Wisp if you wish: put one Pokémon to sleep, and then burn another. Toxic is another alternative status ailment; burn is better on physical attackers though. Hidden Power Ice takes a chunk of life out of Salamence / Flygon.

EVs

At least 148 EVs in Speed and Timid nature for 300 Speed, but max is nice. Spread the rest over HP, Special Attack and Special Defense.

Opinion

As you can imagine Ninetales is fragile but useful. Your team members will sure appreciate the support of sleep, burn and Grudge. You can even make your Raikou beat a team with Blissey in it this way: just Substitute down to low HP while it Seismic Tosses you and to assure you don't get Thunder Waved, and then Grudge to kill all its Seismic Tosses.

Counters

Starmie is the best in the game as Starmie does not care about status, resists Fire, and is fast enough to kill you with Surf before Ninetales can Grudge it. Then comes about every Water Pokémon so Gyarados, Suicune, Swampert, Milotic, and Lanturn, although Gyarados and Swampert don't like being burned. Snorlax, Blissey, Grumpig, Salamence and Flygon get mentions as well but aside from Blissey they won't like being hit by Will-O-Wisp on the switch in. Houndoom can Crunch Ninetales to death rather easily since it's immune to Fire moves itself.

In UU matches, Camerupt is a good Ninetales counter. Wailord can switch in on Will-O-Wisp due to its trait, Water Veil, making it unable to be burned. Blastoise won't care about being hit by Will-O-Wisp and will dispatch Ninetales away quite easily with Surf, unless it gets Grudged. Generally all Fire-types will wall Ninetales though, so if you happen to have one, have fun!