Rule of Nine

How many times have you heard this?

Dude, look. If I have ROTA, Spell Striker, Junk Synchron,

 Quickdraw Synchron, and Quillbolt Hedgehog in my hand, I can OTK!

Uh huh … and if I draw into the 5 pieces of Exodia, I win.  

Outrageous combos in Yugioh are really cool. But, they are something akin to drawing a royal straight flush in Poker.  It’s great when it happens, but it’s not the way to top an event.

The best cards in Yugioh are the stand alone cards.  They’re live every time you draw them.  Dark Hole is a good example.  You may not want to play it the moment it’s drawn, but you generally don’t need another card to make it useful.  

So here’s the question of the day campers.  If a card needs another card to be playable, how many of those other cards should I put in the deck?  

By way of example, consider Malefic Cyber End Dragon.  This card is dead in your hand without a field spell.  Fortunately you can meet that requirement by having any of the following cards:

·         A field spell (e.g. Necrovalley)

·         Terraforming

·         Gravekeeper’s Commandant

·         Demise of the Land

·         Skill Drain

If you use three of each card, you will be adding a total of 15 cards to your deck.  That seems a bit much.  At some point, you will be drawing into all field spell cards and that’s equally problematic.  Fortunately, Commandant and Skill Drain add value to the deck beyond summoning Cyber End.  But, you get the idea.  There should be some optimum number between 1 and 15. 

Of course, there is no perfect number.   This decision will always pit the risk of drawing a dead Cyber End with drawing redundant field spells.  However, I think the optimum number is around 9.  Hence, Yugiold’s Rule of Nine.

The graph below shows the percentage of having a playable Cyber End Dragon for each “Field Spell” you add to the deck.  Increasing the number of field spells from 7 to 8, increases the chance of having a live malefic from 70.5% to 75.2% (or 5.5%). This “marginal advantage” drops with additional field spells. Once you get past 11, you are increasing your odds by 3% of less. 

Of course, your tolerance for live and dead will vary.  Furthermore, this example is pretty extreme.  The Malefics are completely dead without a field spell; most combo oriented cards are only weakened when they are played alone.  Nevertheless, the example is a reasonable one and it should give you a way to analyze your deck.