I'm not going to post a full guide to EV Training (use this guide). However since the guide only has BW1 EV Training spots, we need a hotspot guide for BW2.
The ideal EV Training hotspot has the following criteria:
HP
Attack
Defense
Special Attack
Special Defense
Speed
The ideal EV Training hotspot has the following criteria:
- Wild Pokemon encounter rates for the desired EV are over 60% (100% is preferred)
- Wild Pokemon are as low a level as possible (not strictly necessary)
- Not dependent on version exclusivity or swarms
- Requires minimal use of field moves
- Lowest variety of Pokemon
HP
- Grimer (Castelia Sewers) - Requires Surf - Level 15-17 - 1 HP ** Spring/Summer only
- Stunfisk (Icirrus City) - Requires Surf - Level 47 - 2 HP
- Audino (almost everywhere) - Shaking Grass - Various - 2 HP ** Shaking Grass
Attack
- Sandile / Darumaka / Scraggy (Route 4) - Level 14-17) - 1 Attack ** 75% Encounter Rate
- Mienshao / Druddigon / Golurk (Dragonspiral Tower 1F)- Level 55-58 - 2 Attack
- Golurk (Dragonspiral Tower 2F) - Level 55-58 - 2 Attack
- Banette / Golurk (Victory Road Entrance) - Level 47-50 - 2 Attack
- Druddigon / Zweilous (Victory Road Northeast Cave) - Level 47-50 - 2 Attack
- Patrat / Lillipup / Pidove / Riolu (Floccesy Ranch) - Level 4-7 - 1 Attack ** 65% encounter chance
- Patrat (Route 19) - Level 2-4 - 1 Attack ** 50% encounter rate
Defense
- Sandshrew / Yamask (Relic Castle 1F - 1BF) - Level 18-21 - 1 Defense ** 60% Encounter Rate
- Nosepass / Ferroseed / Klink (Chargestone Cave 1F) - Level 26-28 - 1 Defense ** 54% encounter rate without Magnet Pull, 76% with Magnet Pull
Special Attack
- Litwick (Celestial Tower - 2F) - Level 27-30 - 1 SpA
Special Defense
- Frillish (Verbank City) - Requires Surf - Level 7-15 - 1 SpD
- Baltoy (Relic Castle - Volcarona's Room) - Level 27-30 - 1 SpD
Speed
- Purrloin (Route 19) - Level 2-4 - 1 Speed ** 50% Encounter Rate
- Basculin (Route 19) - Requires Surf - Level 5-15 - 2 Speed
- Rattata/Zubat (Castelia Sewers) - Levels 14-17 - 1 Speed ** 90% Encounter Rate