Pokémon Red and Blue: Route 4 II

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.

	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.

Advance to Cerulean City