This deck started with Avatar of Earth but with Beta that one has been weakened a bit. I have moved the Avatar to Sorcerer, which has proven much stronger. Card draw is key to winning against tournament decks and drawing 2 per turn after your Mana is flowing can overwhelm your opponent.
This deck thrives on fast mana, so runs P-Stone plus the Cores along with the Princess to dig them up. Get to 5 mana and start drawing 2 per turn. Nothing in the deck costs more than 5. You can even just dig for a Core and Stone by ditching any card that isn't a Core on your initial draw though if you end up with all high cost spells it could be an issue. If you can start drawing 2 spells on turn 3 or 4 and pulling 2 spells instead of drawing from the Atlas deck you have a good shot at winning. Frontier Settlers are like a Core that costs 2 mana. So keep your Settlers, keep your fast mana, and mulligan the rest.
You need to get to 5 mana and 2 earth threshold as quick as possible. Pillars are great against Deathdealer but even if not facing that Avatar keep the Pillar in hand for later in the game when you can gain some life back. Just don't let your opponent beat you to it. Smokestacks is in there to stop control decks with Gnome Hollows, Free Cities, Sinholes, and Roots.
Nothing in the deck costs more than 5 mana. Feel free to just dig for spells as soon as you hit that threshold. You are playing the best costed high power creatures in the game. Get them out early and apply pressure. Keep them on defense. As soon as they run out of control it won't take too much to hit them to Death's Door. Common Sense can pull: Root Spider control (Cave Troll) - Death's Door shot or some quick control (Lightning Bolt) - Movement (Blink) - Artifact control (Dispel) - or Movement+Damage (Grapple Shot).