There is something to be said for having a unique perspective. I have been playing Pauper for the better part of ten years and have seen it go from casual competitive to cutthroat to whatever you want to call its current state. I also have been lucky enough to discuss the format and the concept of commons with some of the sharpest minds in Magic and my local playgroups. While some people play Pauper, I can say—much to internal chagrin—that I live Pauper. In doing this, I have come to certain conclusions about the format that the masses may or may not agree upon, so I figured I'd share these thoughts here. Let's begin, shall we?
Flame Slash Defines Removal
Considering the bounty of sweet instant speed removal, it shouldn't make sense that a sorcery speed spell is the premier point and click kill spell. The fact of the matter is that the four damage of Flame Slash takes out every commonly played creature in the format (aside from Guardian of the Guildpact). Sorcery speed on a removal spell that costs one is not a demerit since most of the creatures in Pauper are Mulldrifters and not Baneslayer Angels. In other words, it is their entering play that is the offense and not their ability in combat (see Gray Merchant of Asphodel). In this world, being able to take something out right away is less valuable than being able to do it in a cost effective manner.
So what are the advantages of Flame Slash? Well, it answers a Delver of Secrets on turn 1, which is always important. It also can take out both of Affinity's 4/4s in Carapace Forger and Myr Enforcer. It is soft against RUG Tron and the army of Fangren Marauders and Ulamog's Crushers, but that is a small price to pay for being able to kill, ya know, everything else in the format.
What else does Flame Slash tell us? It places a high value on mana efficiency, which indicates a format that puts a priority on tempo. Being able to trade a full turn of your opponent for one mana is a huge swing and can put the Flame Slasher ahead. Furthermore, look at the most successful decks in recent history, Delver and Affinity—both of these decks accelerate very quickly toward an endgame state. Delver with its early aggression and counterspell backup and Affinity with its free spells shrink the number of turns that matter, effectively turning the tide of tempo. Flame Slash fights these decks on their terms without asking much of the caster.
So what does this mean for creatures? Obviously a card with five toughness is a great way to fight this threat (Nessian Asp, anyone?), but it also means that for a creature to be successful it needs to have some natural resilience to removal. This can be anything from the protection from red bears (Galina's Knight and Vedalken Outlander) to creatures with persist and undying (Safehold Elite and Butcher Ghoul). Even a lowly Doomed Traveler comes out ahead against Flame Slash.
Understanding that Flame Slash is the key removal spell in Pauper gives insight into the speed of the format and the nature of the important creatures, which leads me to my next point.
Essence Scatter Is Underplayed
Not just Essence Scatter, but its comrades in arms Nullify and Remove Soul all seem like reasonable inclusions in blue decks. Since many of the high impact creatures in Pauper come with enters the battlefield abilities, the next logical step is to prevent them from coming into play. Exclude is a common inclusion due to its inherent power and ability to replace itself, but if the format is as tempo oriented as I have posited, then saving a mana is important. Trading two mana for a Mulldrifter or a Gray Merchant of Asphodel seems like a great deal to me.
Is that mana saved worth the exchange of the card from Exclude? Well, it depends. In a deck that wants to shrink the game and does not worry about card economy as much (Delver for example), the extra draw matters less. As the games go long, the value of Exclude increases as it relates to Essence Scatter. So if your goal is to extend the number of turns in a game, then go with Exclude, but if you want to slam the door, use a two-mana option.
Two-Color Decks Are Viable
For a long time Pauper was plagued with terrible mana bases. The advent of Return to Ravnica block last year introduced the Guildgates, which improved the quality of available options. At that time however the metagame was largely established and kept in check with powerful cards like Cloudpost and Temporal Fissure. Since then we have seen the rise of Delver and decks utilizing specialized mana bases (Affinity and RUG Tron). The most recent "best deck" has been Izzet Control, leaning heavily on Izzet Guildgate.
Izzet Control has provided the template for making two-color decks work. The tempo trade of a potential tapped land on turn 1 has to be overcome. Izzet Control accomplishes this with an abundance of removal (including the aforementioned Flame Slash) and a potent card draw spell in Compulsive Research. This lets the deck trade the early tempo hit for increased card quality later. This template can be adapted to other two-color combinations. An obvious option is a B/x deck running Read the Bones. Being able to run a powerful card draw spell alongside the stellar removal available in black gives deckbuilders options for other midrange decks.
There are definitely other avenues out there, but it will take some time and testing for these decks to be discovered. Currently the incentive for brewing and coming up with new ideas in Pauper is low. This leads to the same decks doing well with few people innovating. This isn't good or bad; this just is a reality of the fact that Pauper is a low stakes format. Those that put in the effort will discover the unexplored niches of the format, and to me there seems to be a lot of virgin space in the two-color realm.
Brainstorm Isn't A Powerhouse
One of the allures of Pauper is the ability to run some powerful commons. Brainstorm has quite a pedigree as the backbone of Legacy and is restricted in Vintage. In Pauper you can run all four. Frankly, I think the card is pretty awful in the commons-only format. The lack of strong fetch lands turns Brainstorm into a fine card selection tool but a poor card advantage engine. While people often try to make Brainstorm and Squadron Hawk work, the investment in so many cards can often dilute a deck. Brainstorm is good, but it's no Jace, the Mind Sculptor. Jace in Caw-Blade would be part card economy buster and part game ender. In Pauper the Brainstorm and Squadron Hawk duo can draw cards, but so can Compulsive Research.
Often people just entering Pauper ask about cards that were powerhouses at one time in other formats and get disappointed when they hear they see no play or are just bad. The truth of the matter is that regardless of Pauper's perception as a "weaker" format due to it being comprised solely of commons, context still matters. Raw card advantage matters more than card selection, and getting more mileage out of each spell has a greater impact than nifty interactions. This is why spells like Firebolt see play (and why spells like Strangling Soot and Crippling Fatigue should get more chances). So Brainstorm, a powerhouse in formats with other powerful cards, falters in the most basic Constructed format.
Delver Isn't All That Good
This might come as shock. Delver Blue has been the most heavily played deck in Pauper for the better part of a year. It has multiple high level adherents as cheerleaders. Heck, I won't argue the little blue Human Wizard defines the format.
But Delver is The Rock.
You know The Rock. Good against the field, great against nothing.
Yeah, that's Delver.
I have been tracking the metagame data since last July, and while it's the most heavily played deck by a mile, Delver rarely puts up the most wins per appearance. It regularly Top 8s Premier Events and makes the finals of single-elimination queues, but it's far worse at closing the door than a deck like Affinity or the more controlling blue decks.
Why is this the case? Delver is great at shrinking games down to a few turns. An Insectile Aberration backed up with Spellstutter Sprite or Counterspell can limit the amount of time an opponent has to act. However, as the games go longer, Delver's advantages go downhill (Flame Slash shines here because it can answer a turn 1 Delver of Secrets while maintaining utility later). Affinity, arguably the most successful deck of the same time period, pulls a similar time shrinking trick, while Delver prolongs a match to the point where that early tempo advantage does not matter. Izzet Control is similar in that it runs enough removal to simply not care about the turn 1 and two-drops out of the tempo deck.
Delver's success may also be hurt by its popularity and the abundance of players cutting lands. Mezzel was one of the most successful Delver players of last year and did so on the back of a list running nineteen lands
Most lists today run sixteen or seventeen lands and are stitched together with Ponder and Preordain. While the Turbo Xerox guide tells us that every one of these cards can negate the need for half a land, if the format is as centered on tempo as I believe, using these spells to find lands and not spells can be a huge detriment to victory. One only needs to look at the relative success of the land-"heavy" control Delver lists to see the correlation between hitting land drops and victory.
I don't want to imply Delver is a bad deck; any deck that wants to get serious consideration as a contender in the format needs to have a plan for the blue menace. Instead, Delver is a misunderstood deck, and the information cascade of some suboptimal lists being popular has led the deck astray.
So that's my take on certain attributes of Pauper. I'm fully prepared to be wrong, but I don't think I am. Pauper is a deep format that maintains a vast area of unexplored design space and understanding. I'd would rather be wrong and spark discussion than keep silent and not question what's accepted.