I am currently doing a playthrough of Pokemon Yellow. My Charizard currently knows Flamethrower, Fly, Slash and Dig. Flamethrower is pretty much the best Fire-STAB it gets, Fly is STAB and necessary for getting around the region. Slash gets an amazing base power of 140 since it pretty much crits every time. But now I'm questioning if I should replace Dig with Fire Blast. Dig is really good for dealing super effective damage against other fire types, it's weaknesses rock and electric (and also poison-types). Although it takes some time to attack and you are vulnerable to Earthquake and Magnitude. Fire Blast is like a more powerful Flamethrower to be used when... needed. When I say it like this Dig sounds more reliable but again it has a really low base power and Fire Blast has a lot more power. My question is then: Dig or Fire Blast? Thanks in advance. (:
I think you should keep the moveset you have now. Fire blast isn't that good of a move for in-game use because it has low PP, so a Charizard that relies on fire blast won't be able to fight many battles in a row. On the other hand, you can use dig to instantly escape caves, even if it's useless in battle.
Fire Blast because it's stronger than Flamethrower, it gets STAB, and Charizard is better at special attacks like Flamethrower and Fire Blast than physical attacks like Dig.