So, statistics. They're important when it comes to children's card games. Knowing how often you'll open up with a card/combo you want can help you decide if you want to play a deck that depends on said card/combo.
For instance, Flamvells. They rely entirely on Firedog, and opening with it often leads to victory. The chance of opening with a card that you have three copies of in a 40-card deck in your starting hand is a little less than 40%. That's fairly low, but it's a good enough card at most times during a duel, so you wouldn't mind drawing into it a little later. It can also be searched by Flamvell Poun.
The main example I wanted to address today was Gravekeeper's. First is Necrovalley. Assuming that a Gravekeeper's deck plays two Necrovalley, three Commandant, and three Recruiter, there's a little over 76% chance that a starting hand for that deck would open with a way to access Necrovalley. Pot of Duality and/or Upstart Goblin would increase this chance, of course.
As for the amount of Monsters commonly played in Gravekeeper's (14), there's a lot more to look into. So, here's a little table to show the percentage of opening with a certain amount of Monsters in the starting hand, as well as the chance that a Monster would be drawn as the seventh card if specified number of Monsters had been drawn in the starting hand. Note that these percentages are for a 40-card deck with 14 Monsters.
| Number of Monsters | Starting Hand | Next Draw |
| 0 | 6.00% | 41.18% |
| 1 | 23.99% | 38.24% |
| 2 | 35.44% | 35.29% |
| 3 | 24.66% | 32.35% |
| 4 | 8.48% | 29.41% |
| 5 | 1.36% | 26.47% |
| 6 | 0.08% | 23.53% |
So, there's about a 94% chance that a Gravekeeper's player would open up with a Monster in their first six cards. That's pretty good. That is, until you realize that Descendant and Assailant aren't exactly amazing on their own, and Commandant is used as a way to get to Necrovalley.
You would also notice that the chance of drawing a Spell/Trap far out-weighs the chances of drawing a Monster. That's how the deck is built to run. There's a problem with that, though. Once your Monster dies, you can't really do anything, except hope to draw into another Monster.
This is the fundamental flaw with Stun decks. Monsters do not last very long at all in this game. They can die the moment they're summoned, and would be lucky to live a few turns. Playing so few Monsters is risky, since they are the cards that win games.
Moreover, this leads into explaining why certain other decks are so inconsistent. Hopeless Dragon decks win when they draw Future Fusion, right? Well, even with two Gold Sarcophagus, they would barely get to it half the time.
Hopefully, this will help you make better decisions when it comes to playing more consistent decks or figuring out what an optimal Monster/Spell/Trap ratio would be, or something.
