About
Confluence is a Commander (EDH) mana base calculator. Paste a decklist and it tells you how many lands to run and how many sources of each color you need — applying Frank Karsten's hypergeometric consistency math automatically so you don't have to.
Why this exists
I'm someone who can't help but optimize things. That's what drew me to Karsten's land base articles, since they're grounded in real probability calculations instead of rules of thumb. I've been using his articles to build optimal land bases for a while now, but it's always been tedious and slow. Ultimately, we Magic players just want to cast lots of cool spells and 'do the thing'. But we need to actually be able to cast those spells — and that means having a good land base. Building the color-fixing in a land base is boring, but it is important. This tool is here to speed that part up.
It's aimed at anyone building an EDH deck, from newer players who just want a sane land count to veterans tuning a specific mana base.
What makes it different
- Faithful to Karsten. It implements all the formulas and calculations from both his articles: "How Many Lands Do You Need in Your Deck?" and "How Many Sources Do You Need to Consistently Cast Your Spells?".
- Credits nonland mana sources. Most calculators only count lands. This one also gives fractional source credit for mana dorks, mana rocks, and card draw — so your colored requirements reflect your whole mana base, not just your lands.
- Interactive. After analysis you can toggle which spells count as "key spells" that you need to cast on curve, and which non-land mana sources to credit, and the numbers recompute live.
How it works
- Paste a decklist.
- The app fetches card data from Scryfall and classifies each card (lands, cheap card draw, ramp, mana dorks, mana rocks, MDFCs).
- It computes a recommended land count and the colored sources needed per color and color combination, then shows the breakdown with the binding spell driving each number.
- Choose the land cycles you want to include as options for your deck. It will compute the optimal combination of color-fixing lands for your deck.
Credits
Of course, huge credit to Frank Karsten for coming up with all this math:
- Land count — How Many Lands Do You Need in Your Deck? An Updated Analysis
- Colored sources — How Many Sources Do You Need to Consistently Cast Your Spells? A 2022 Update
Card data provided by Scryfall.