Technically you could evade nonstop and never get hurt, and still have a chance to hurt the other pokemon. Okay, let me give you guys tips on how to get the surfing/flying pikachu.
Read it all and you'll probably have a better chance to catch them! :) For the basics.
The first thing to understand is that each stroll area has 6 pokemon that can be caught in the area. Those are divided into Group A (Rare pokemon), Group B (Uncommon), Group C (Common).
Each of those 6 pokemon are paired off into each of the groups. That means each area has 2 pokemon in group A, 2 in Group B, and 2 in Group C. This is the current grouping for Yellow Forest.
Group A: Surfing Pikachu or Flying Pikachu
Group B: Volt Tackle Pikachu or Flail Pikachu
Group C: Normal Pikachu or Normal Pikachu
Let me also make this CLEAR to you. Every single one of those 6 pokemon in each area are FIXED. That means they are always the same, same gender, same attacks. The only thing that changes is nature, stats. Their levels are also always the same. The common pikachu will be level 10. Flying pikachu will always be level 15 (btw, flying pikachu also already knows thunder O_O).
When you go into a stroll, the game assigns you one pokemon from group A, one from group B, and one from group C. So until you end the stroll and start another, you will be stuck with those.
When you use the pokeradar in the pokewalker. There are 4 levels.
First ! : It's a pokemon from group C
Second ! : Either a pokemon from group C or B
!! : Either a pokemon from group B or A
!!! : It's a pokemon from group A
(You need 10,000 steps to unlock flying pikachu, 9,500 for surfing pikachu, 5,000 for volt tackle pikachu, and 2,000 for flail pikachu. This means until you have the steps necessary that pikachu won't be one of the ones you can find)
TIPS: Now for the real tips & advanced info now that you know the basics.
- When you choose to "Send gift" instead of "Return from stroll", you'll receive the pokemon and items that you got, but it won't reset the pokemon assigned to your stroll. Use this to your advantage. What you should do is get to 10,000 steps, catch 3 !! pokemon (of course if you see a !!! catch it!), send them through gift. Odds are at least one will be from group A. Check their moves, and you'll know if you've been assigned either surf, fly, or volt tackle. Once you have the one you like don't return from stroll until you get as many as you want from that pikachu type. When you send gift you will lose your watts, so be careful.
- BIG TIP: Each stroll area has pokemon types that give advantages. For yellow forest it's electric, ground and grass. What these type advantages does is it decreases the amount of steps needed to catch group A pokemon by 25%. Meaning the first thing you should do is catch whatever pikachu, end stroll, and switch a pikachu in. Having an advantage type also INCREASES chance of encountering a rare pokemon! So with a pikachu on the stroll it only takes 7,500 steps and it'll be easier to catch rare ones!
- Never evade unless you have only 1 hp and the opponent still has 4. Rare pokemons have an extremely high chance of running away. And they tend to evade a lot, so you'll "stare down" (a tie, where nothing happens). Until they run away. (For those that don't know at a catching fight on the pokeradar you have 3 options. Attack. Evade, and Catch. If you attack and the opponent attacks, each loses 1 out of 4 hp. If one attacks and the other evades, the attacker will miss and the evade will attack for 1hp bar. If both evade, you just "stare down".
- Always grab 3 items before sending gifts to make the most of your watts. From this place you can get a light ball, mystery seed, thunderstone and even big root :)
- Although you lose your watts from sending gifts, you don't lose steps. Meaning once you send gift, all you need left during that day is watts.
- Don't waste your energy shaking the walker. Grab a fan, point towards ceiling, put pokewalker on it. Small vibrations are enough to register. Feel free to ask any questions! :)