Route 4 is a short route connecting Mt. Moon with the next town in the game. There are a couple of gems to be found here.
On the small plateau east of the exit of the mountain, examine the empty space to find a hidden Great Ball, which is 1.5 times more likely to catch a Pokémon than a Poké Ball. Use this one wisely, because you cannot buy them in bulk for a while. If you're looking for a Clefairy, it can make the capture much less tedious, but be sure to lower its health first.
On the large plateau further east, you can find TM04 Whirlwind, which will allow you to flee from a wild Pokémon by blowing them away, but does absolutely nothing in trainer battles.
Note that when you jump down the ledge near the grass, you will not be able to return to Mt. Moon, Pewter City, or any past locations for a while. When you're satisfied with your perusing all of the locations so far, hop down the ledge and catch one new Pokémon, depending on the version you're playing.
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Rattata |
Normal |
L8-12 |
40% |
 |
Spearow |
Normal/Flying |
L8-12 |
35% |
 |
Ekans |
Poison |
L6-12 |
25% |
0% |
 |
Sandshrew |
Ground |
L6-12 |
0% |
25% |
Ekans and Arbok
Ekans specializes in Attack and Speed. It evolves into Arbok at level 22. It's stats are bad and it is weak to Psychic.
It's only potential is to train it for Speed in single player and use Wrap, but this is a time consuming strategy and it is outclassed by other Pokémon in every aspect.
Sandshrew and Sandslash
Sandshrew has decent Defense for an unevolved Pokémon, which makes it a good companion for beginning Blue players. Parallel to Ekans, it evolves at level 22, into Sandslash. It's Defense increases to a decent level for an evolved Pokémon and its Attack is okay.
Competitively, Sandslash is outclassed by the staples, Golem and Rhydon. Anecdotally, however, it can defeat them both. It makes good use of Swords Dance and Earthquake and has access to Hyper Beam, Rock Slide, Body Slam and Substitute. Swords Dance gives it an edge against its biggest counter, Exeggutor.
As its Attack stat is not great, Swords Dance and lucky Body Slams are required for its competitive use.
When you're satisfied with your perusing all of the locations so far, head east into Cerulean City.
Welcome to the first of the eight gyms of the Indigo League, Pewter City Gym.
You can avoid the gym trainer by walking on either side of him; however, experience is always valuable to collect. He is a Jr. Trainer♂ who uses a Diglett and a Sandshrew at level 11. They are impervious to Pikachu's Electric attacks and their Normal-type attacks can do a lot of damage.
After defeating the gym trainer, step forward and face Brock.
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|
|
|
Leader Brock |
Pewter City Gym |
2 Pokémon |
P1386 |
 |
Geodude |
Rock/Ground |
L12 |
Tackle |
Normal |
Defense Curl |
Normal |
|
|
 |
Onix |
Rock/Ground |
L14 |
Tackle |
Normal |
Screech |
Normal |
Bide |
Normal |
Bind |
Normal |
If you have access to Bulbasaur's Vine Whip, Squirtle's Bubble or Butterfree's Confusion, then this is an easy battle. Even so, beware of Onix's Bide, which will deal double the damage it received over two turns. This can take out one of your Pokémon if you're not paying attention.
If you don't have any of these moves, then spam your most powerful attack and heal when you are low on health.
Upon defeat, Brock will award you with the BoulderBadge. He will also give you TM34, which contains Bide. Don't be hasty about using this on one of your Pokémon, because you only get one TM34 in the entire game.
When you're done celebrating, exit the gym and head east onto Route 3.