A small word ahead. This "article" started as a reply to Eric Turgeon's article, so when I refer to "you" i mainly mean Eric, but use context and common sense for any exceptions.
After writing most of this, I realize that the subject has shifted from popular manafixers in budget decks to manabase construction in general, which is the main reason I've submitted this as a separate article.
Those are some solid arguments you provide, but I would like to add my personal experiences.
I learned magic from a good friend of me, who had bought some portal starters. After he explained the basic rules to me, we each chose a random color (6 sided die, ignoring the 6) and build a deck of that color.
Rule of thumb here was 1 in 3, meaning indeed 20 lands and 40 spells.
I didn't need more lands, as anyone who has played with portal knows that you only need mana to play spells, portal spells have no activated abilities (as far as I can remember). This basically allowed us to curve out quite easily and monocolor results in an inability to colorscrew.
Over time my ideas about mana have changed a lot.
Basically, I build 3 kinds of decks.
First, I play a lot of limited. Limited decks consist of at least 40 cards, although I end up on 41-42 most of the time. Running 14 lands here is basically a free ticket home. Reasoning here is that it's almost impossible to end up in a single color without splash in limited. Your cardpool will simply not be strong enough.
Secondly, I build quite some constructed decks, mainly legacy and extended. You all know that 60 cards is mandatory here, but the amount of land differs greatly.
Ignoring exceptions like 2-land belcher, kobolds-land grant, 43land.dec etc, a normal constructed deck has between 20 and 26 land.
Finally, I have played my fair share of wacky formats, including (but not limited to) Highlander, prismatic and Elder Dragon Highlander. These kinds of decks have between 100 and 200 cards, thus require a delicate manabase.
In all formats, the number of lands you play isn't deducted from applying some sort of formula to your manacurve, although the curve obviously plays an important role.
Far more important however, is your game plan. Take a deck that has been quite popular in the past years: Goblins.
Goblin-decks, whether it's with the old lackey or the more recent earwig squad, all have the same thing in common. Every land after the third (sometimes even after the second) is a dead card. Dead cards make a dead player, thus goblin tries to minimize the risk of drawing blanks in the mid to lategame, by playing fewer lands. I'll mention fetch here, and will return to this subject later, as it plays an incredibly important role in the creation of a manabase.
On the other end, we have a combo deck such as reset/high tide. For those of you that aren't familiar with this deck (if you don't know how goblins get to work, stop reading ), it simply plays island go, then, when it has to, it'll create a lot of mana with high tide and reset, then draws a lot of cards, finishing with either a big stroke or a brain freeze with a storm count of 20-30. This deck wants to lay a land every turn, and can't realistically finish with 3 lands (although 4 is possible, the more the better).
Both decks with usually run about 20 lands (on a total of 60 cards).
Goblins because it doesn't want to draw more, Solidarity because it has stuff like brainstorm to search for lands.
As Eric made clear, maths are important to see how often you'll draw the number of lands you need. This is however just the first step (arguably the second, if you count the amount of land you want as a separate step). After this, you have to take a look at your deck to see what you can do to ensure extra stability.
Best example is obvious a green deck. I've run as much as 20 lands in uG opposition, and never had any problems because I had 4 birds of paradise and 4 llanowar elves.
This brings me to my main point here. When determining the number of lands you'll need, you have to take into account the number of nonland manasources you have. You can't really count 'm as lands (excluding moxes), but for the budget players around here, ravnica block signets are a source of mana, but you'll need to get to 2 mana before you can play them.
Here's a small step-by-step guide to creating a manabase for your (constructed) decks.
Determine how many lands you require to execute your gameplan. (not including other manasources).
If this number is 0, you don't really need lands; although a few can be good as backup (you will need mana).
2-land belcher is a good example, it runs two lands, but can perfectly manage to go off from just Lion's Eye Diamonds, Lotus Petals and rituals.
If you need at least 1, you will most likely still be having a combo deck, and I recommend about 10 lands.
For example, my dredge deck has no need for more than 1 mana (although I wouldn't mind the second one either), but I do need one. Having more than 10 lands increases the chance of me getting 1, but also increases the chances of having more than one, which is something i normally want to avoid.
If you need 2, you're entering a "twilight zone". You're still running combo, in which case it's very hard to determine a good landcount, but 15 is a good number to start with.
I can't really think of a good example of a deck here, maybe flash hulk in vintage, although that can go off with 1 land just as easy. (See step three)
When the answer is 3, we're entering the realm of aggro decks. Like I've said before, you'll want about 20-22 lands, depending on the amount of 1 and 2 drops in your deck.
If you need 4, you'll need to add just a few more, the 24 mentioned in Eric's article will do just fine.
In the case that you want 5 lands or more, it's generally the more the better and we can say hello to control decks.
Control wishes to miss as less landdrops as possible, for example, if youíre playing control against goblin-aggro, you will want enough mana to cast a Damnation, but still be able to counter that Patriarchís Bidding.
I would never run more than 24 lands, which is a bad idea in any case except in very specific decks in which you have a plan with them (say, Life from the Loam).
As a final note, these numbers are only initial. In the next few steps I will modify these amounts, depending on the acceleration in the deck.
Now that we've got the basic number of land, we can start applying modifiers, which are deck-specific.
This is the second step, where we take the maths of Eric into account again. If you feel comfortable with less land (like me), or think that a chance of 84.4% chance of getting 2-5 lands is not good enough, as you'll rather play with 3 or 4 (chances of which are 50.5% in a 24/60 land/total ratio).
See how many nonland manasources you have.
If you have none, there is nothing to be changed, but a lot of decks will use some. Whether you use a chrome mox or a simple fyndhorn elf, each one of them makes you less dependant on your land. If you have a lot of acceleration, you need less land. A lot of cheap mana-generators means you can cut quite a lot of land. As a rule of thumb, you can usually remove one land for every 3 nonland manasources that cost 2 or less mana to play. For more expensive things, such as Thran Dynamo or Gilded Lotus, you shouldnít remove land, as youíll have to cast them first.
Use common sense here, type 1 moxes can obviously replace land on a 1 on 1 ratio, while the aforementioned ravnica signets need mana to operate.
Take a look at manafixers.
A manafixer is something that doesnít creates mana from itself, but can be used to fetch (oh dear, thatís not a clue, see step four) something that does. This is quite a broad definition, but it has to be, since even Intuition (for Cabal Ritual, Cabal Ritual, and Cabal Ritual) could be considered a manafixer.
If you have some green in your deck, you have access to the majority of manafixers, including Sakura Tribe Elder, Land Grand, Search for Tomorrows and many, many more. Other colors are more limited, but still can use things like Braidwood Sextant, Dreamscape Artist, Wanderers Twig, Land Tax, Oath of Lieges, etcetera.
When I use manafixers I generally donít run less land, they simply function as deck-thinning mechanisms. The reason for this is that I donít use them to get another manasource, I use them to get another colorsource. If you are running a deck with more than two colors, itís almost impossible to build a stable deck without them.
The five Onslaught fetchlands (Windswept Heath, Flooded Strand, Polluted Delta, Bloodstained Mire and Wooded Foothills) are arguably the best lands in the entire game. Most of these reasons are obvious (it isnít hard to spot why they are better than mirage ďfetchlandĒ, which come tapped into play).
First of all, the only format that currently hasnít got any dual lands is standard, and fetch isnít legal there, so that isnít much of an issue. Duals give you the option to search for all five colors with a single fetchland. As long as you have the duals, you can search whatever you want, whenever you need it.
In addition, you can use them to fetch basic lands if you are facing a lot of nonbasic hate (price of progress, back to basics, blood moon or wasteland) and still get the colors you need!
Second, they remove land from your deck. With less land in your deck, youíll draw spells more often, giving you a great advantage over your opponent. Card advantage is extremely important (if you havenít already, I really recommend reading [url="http://www.starcitygames.com/php/news/expandnews.php?Article=3690]this article[/url]
Finally, they give you options. If you have a for example a starting hand with (among others) a Watery Grave, a Polluted Delta and a Force Spike, you can choose to start with a tapped watery grave, but then you lose the ability to play your Spike. If you start with a Delta out, you can wait to see if your opponent plays anything that is worth countering, if so, you can fetch an island and counter it, and if not, you can use the delta at the end of your opponents turn, fetch a different Watery Grave, and let it come into play tapped, so it untaps straight away. Fetchland allows you to bluff, hoping your opponent wonít play a strong spell on turn one, or allows you to kill it where tapped land (or a wrong colored land) would fail you.
To sum it up, if you have fetch, thereís no reason not to use them in every deck you build!
What land to use?
Now that you have a rough idea how many lands you want to use (itís usually safe to deviate from the standard by adding or removing a land), itís time to take a look at the composition of your manabase.
When you have a single color, itís fairly easy, add basic lands and fetchland, and start testing. You can use some lands that can be better than basic lands, for example Rustic Clachan, which can serve as a combat trick lategame or Flagstones of Trokair, which can serve as a deckthinner when you draw the second (theyíre legendary).
Most decks however will have more than one color. Here it gets a little tricky. First youíll have to examine your collection to see if thereís anything that produces mana of all the colors you need, or at least two of those colors. Lands that give you all the colors you need should always be played (unless they have a nasty drawback, such as Rainbow Vale). Let us for the sake of simplicity assume that we either are a beginning player with a limited collection (or a budget player for that matter), and only use basic land.
A deck you wish to play consists of 60 cards, 37 of which are spells.
We have a total of 12 red, 17 blue and 8 green cards. When we take the most obvious approach, having the same red:blue:green ratio in lands as we have in spells, we get 7.5 mountains, 10.5 islands and 5 forests. Itís up to you to decide which one youíll round up, and which one down. This is a good start, but cards are more complicated than that. Some cards need two colored mana, and we havenít taken this into account yet.
Staying with the same example, we add all colored mana symbols on our spells together, resulting in 19 red, 21 blue and 9 green symbols. If we add land to match this ratio we get 8.9 mountains, 9.9 islands and 4.2 forests. Now it gets a bit trickier, as we will have to make some compromises. Taking the mean of both values results in (rounded down or up appropriately) 8 mountains, 10 islands and 5 forests. When you just use basic land this will be the best solution, but every player will have some nonbasics lying around.
If you have lands that produce mana of multiple colors, replace a basic land of one of those colors, preferably the color that will miss the single colorsource the least. This is especially important with lands that come into play tapped. Letís say that you opened a booster dissention, and opened a Simic Growth Chamber (GU bounce). In this example itís obvious it will replace an island, as that will be missed leased. But what if we trade some cards for a Gruul Turf. If we have a lot of red 1 mana spells, such as mogg fanatic and kird apes, it will probably be better to remove a forest from the deck, and put the Turf in.
When tuning your manabase, consider first if the card you want to add would really make your deck better. Bouncelands are good for some decks, but in an aggrodeck you canít afford to ďwasteĒ a mana by having the Turf come into play tapped.
If you are sure the card fits in your deck, see what you can safely remove. This is a decision you can make based on the amounts of lands already in the deck, but also on your experiences. If you often find that a first turn island is unused, you can substitute an island for a Breeding Pool, because you can safely let it come into play tapped.
The most important thing I would like you to remember is that your deck will depend for 100% on your manabase. You donít win by casting your fireball for 20 points of damage, you win by having the lands you want, exactly when you need them!
While you are building a deck, give the manabase some very serious thoughts, itís really more than just maths, donít just add some lands at random, because you will want to mulligan as few times as possible. With a strong manabase you can decreases chances of a manascrew and a colorscrew, and therefore win a lot more games.
Good luck creating your new deck!