Start typing a card name and use the auto-complete feature to quickly select the card you're trying to add. Enter a quantity and add that card to your sideboard!
Submit a list of cards below to bulk import them all into your sideboard. Post one card per line using a format like "4x Birds of Paradise" or "1 Blaze", you can even enter just the card name by itself like "Wrath of God" for single cards.
This deck has been viewed 857 times.
Now normaly when I see a goblin deck, I immediately think Krenko. But that would be to obvious. Instead I'm going to suggest Goblin King for your sideboard.
Oh and you could make do with less land in my opinion.