The style of Baton Pass requires a very mixed level of aggression. Not too much, but enough. You don't need +6 all stats to get kills with Espeon. And you can't expect to get kills with only +3 speed. The trick to being successful with this team, in a nutshell, is knowing your power at various stages throughout the meta.
By this I mean, you should know the answer to the following questions at every point in the game:
- How much damage can I deal? - This goes for Vaporeon, Zapdos, Espeon, and Ninjask for extent. For the following
- Vaporeon: How much can scald do to this Pokemon at this stage? The main things you need to know are if you can 1HKO a frail special attacker, or 2hko a physical attacker lacking priority when you are faster. Many times you can switch in, tank a strong hit, and kill the threat that has been bothering you all game.
- Zapdos: How much damage can Thunderbolt do at any stage (+0, +1, +2, etc.) and after using Charge, which gives a bonus. A charge boosted Thunderbolt can kill a lot more than you would expect.
- Espeon: You should know how many defensive boosts will allow stored power to deal specific damage, and you should know what happens when special multipliers are added in as well. This can get tricky, but eventually you will learn that many pokemon like Breloom, Tentacruel and Toxicroak can all be 1kho with minimal boosts.
- Ninjask: How many turns of stall can I give myself with my remaining life in order to stall out this player?
- How much damage can I tank? - If you switch in, will you die from the attack and SR? You should also know when you will take <25% damage so you can know to boost or sub.
- How fast am I? - You need to know if you are able to outspeed the threat, this is normally not a problem. But involves priority. Dont leave a sub down on Mr. Mime if scizor can 1hko with bullet punch, etc.
Having the answers to these questions will make prediction much easier. Say for instance you are boosting behind a sub with zapdos and a scarfed terrakion comes in with a Stone Edge. Instead of switching to Scizor to tank it and boost, you also can charge, as the sub breaks, then 1hko with thunderbolt on the next turn. Too often do people just focus on boosting instead of getting easy kills.
On the same note, don't try to kill something you can't. Don't switch in Espeon only to find out that you can't kill the Blissey and it kills you with Seismic Toss. If your trouble comes specifically with Espeon, then I'll give you a general rule of thumb to follow:
1. Pass to Espeon when you have a Sub up to protect Espeon from an incoming crit.
2. Pass to Espeon when you have max defense (even if you have no SpA). Unless the enemy has a dark pokemon, you don't need any SpA to sweep with stored power.
3. Pass to Espeon when they present a frail attacker that is weak to your STAB.
Don't worry about Stealth Rock. The majority of my games I Substitute during the Stealth Rock, Protect twice and then Baton Pass from Ninjask. Stealth Rock doesn't need to be reflected unless you see a team preview that would require a lot of switches, like perhaps a Perish Song user or some Volt-turn with priority attacks.
More about
team preview: Look for the threats in the threat list. Look for easy kills with any pokemon at unboosted levels, as well as pokemon you won't be able to kill. Also look for priority users and scarfed threats at lower speeds.
That's about all I can think of for now, but as an overview:
In order to succeed with this team, you must have a general knowledge of the damage you can deal and take at any stage of the game with a variety of mixed stat boosts. Know when to get easy kills and know when to play defensive. Prediction doesn't need to be anything crazy, if you see a special attacker, switch to Zapdos or Mr. Mime. If you see a physical attacker, switch to Vaporeon or Scizor. (Again, remember switching isn't always required, as sometimes you can kill the enemy outright).
The "prediction" comes more into play with prankster users and specific threats like Politoed. Like for Politoed its beneficial to dry pass on those in order to stay ahead of the switch in and put in Mr. Mime, Zapdos or Espeon. Mr. Mime provides full defensive tactics, you are only wanting to calm mind safely and quickly. Espeon is the opposite, you want to kill this Politoed asap or scare it away with a Stored Power. Zapdos is mixed and gives you the option of using Thunderbolt to kill it, while also allowing you to predict a switch and simply charge or pass again to stay ahead. Mr. Mime is the safest choice, while Zapdos is the hardest to pull off, but often more rewarding. However note that, none of this is required but only makes it easier for you. For an average game, as you can sit with Scizor behind a sub, see the politoed switch in, and pass to Mr. Mime to block the SpA or Perish Song.
