I have been reading a lot about various Magic strategies lately and I have been oddly confused by many supposedly tournament quality decks. If you have looked at my deck designs you probably noticed I tend to put fours of most all cards and occasionally 2 of. Looking at decks online I noticed a great many decks use 3 of and even 1 of cards. I have also found there is little concern for the mana cost of cards and most deck designers have no problem putting 5, 6 or even 7 drop cards in their decks. As I understand it most modern players expect games to go on for 10 or 15 and occasionally 20 rounds. I have to ask myself has no one explained the mana curve to modern players?
The first thing to understand about strategy is the most important time of the game is the first three rounds, you first 10 cards. The first three rounds are the early game, the time in which you have few resources in play and many cards in hand. During this time you do not want to miss any land drops, you absolutely must play a land every turn, which means at least three of those first 10 cards need to be land cards. This is why everyone recommends at least 1/3 of your deck be land or 20-24 land. If you are playing a mono colored deck you can get by with 20, if you are playing two or more colors, go with 24 or maybe even 26. The second thing about the early game is you want to be able to cast something every single turn, you need to start establishing your game from the very beginning. So of the seven cards left after your three lands, you must have at least three cards that can be cast on three or less mana. Realistically, you’d probably rather have three one mana card in your hand than three three mana cards. By extension, the majority of the cards in your deck should cost one mana. A near perfect early game would be made up of three land, three one mana cards, two two mana cards and two three and higher mana cards. A nice mana distribution in a deck should look something like this.
What this translates into the establishment of your strategy very early in the game, mounting small but effective threats and the ability to answer your opponents threats. If done properly, the game will not progress to the 10th round and your deck will function fine on three mana. When I am deck designing, I build my decks for short decisive battles, by the 5th or 6th round I should be mounting my primary offense and the other player should be recognizing his impending doom.