Two weeks ago, I knew next to nothing about Invasion Block Constructed. A week of testing and a Grand Prix later, I'm still a long way from knowing everything, but I do think I understand a lot of what is going on. In analyzing a format, it's best to begin where it all begins. That's almost always with the most direct and efficient beatdown deck that can be played, and in Invasion Block that would clearly be red-green. It's also a subject I know a lot about, since the deck is essentially unchanged by Apocalypse. In his article on the deck, Brian Kibler explains the deck's success in terms of Threat/Answer theory. While what he says definitely has truth to it, I think the reason this deck is still around is more than just that it attacks and kills fast with nothing but creatures and removal. The key is that red-green manages to assemble a remarkable amount of staying power while assembling the format's fastest beatdown. Red-green isn't about putting out fast creatures and burn spells, it's about the threat of Flametonge Kavu and Thornscape Battlemage and the threat of kicked Kavu Titans and Skizziks. After sideboarding, this strategy can be emphasized in the matchups where it is important. A good example of the 'standard' decklist for red-green is the same one Kibler took from the Toronto qualifier:
Jason Means Worlds PTQ Winner
1 Keldon Necropolis
4 Shivan Oasis
2 Flametongue Kavu
4 Raging Kavu
4 Blurred Mongoose
4 Kavu Titan
4 Thornscape Familiar
4 Thornscape Battlemage
4 Ghitu Fire
4 Scorching Lava
2 Urza's Rage
3 Jade Leech
4 Thunderscape Battlemage
1 Urza's Rage
2 Flametongue Kavu
To begin with, look at the red-green deck in terms of its development over the first few turns. On turn one it will do nothing, as will most of its opponents. The only one-drop in the format is Stormscape Apprentice, with three copies in most versions of The Solution. On turn two, the deck will play a two casting cost green creature. The ideal creature to play is normally Thornscape Familiar, but in other situations the deck may prefer to lead with Blurred Mongoose. If neither is available, the deck falls back upon Kavu Titan. In a desperate situation, Scorching Lava or occasionally Ghitu Fire can keep the deck on tempo instead. Both the Mongoose and the Familiar start the deck out toward creating a situation the opponent likely has a hard time getting out of.
The Mongoose creates an attack that can't be countered or targeted, and the deck contains a lot of burn to clear the way. If a creature gets in the way, the plan is simply to remove it. It is ideal when the opponent sits back on a counter on turn three and it runs into a second Mongoose. At this point, any creature the opponent puts down before turn five is going in exposed to Flametonge Kavu and Thornscape Battlemage as well as simple removal, with a five-turn clock already on him. Outs like Void expose the opponent to a Skizzik. Only an opposing Mongoose or something like Pernicious Deed will provide the needed kind of relief without letting the red-green deck's strategy work its magic. A Spectral Lynx with mana up exposes only to Scorching Lava but lets a Flametonge Kavu into play followed by another four point hit, perhaps worse.
With the Thornscape Familiar, things are even more menacing. The deck is representing the ability to cast Flametonge Kavu on turn three, and that makes any response with a vulnerable creature highly dangerous. Only Galina's Knight and Blurred Mongoose are safe. On turn four, the deck threatens with Skizzik. This often forces the opponent to hold back his creatures in favor of counters or Repulse, letting the red-green deck seize the tempo of the game. Playing against red-green is like playing against a very aggressive chess opening, and the threats are often stronger than their execution. The other player's head is filled with visions of being burned out or having their creatures die to a Thornscape Battlemage or Flametonge Kavu. The downside to this move of course is that the Familiar can be removed, which puts the players even again.
No matter what the opening, the essential situation becomes a struggle for the opponent to play his cards out without exposing himself to red-green's 187s and large monsters, and without falling into burn range. This will end many games quickly. The question is what to do afterwards if the strategy fails, which leads to the question of why it failed. There are several ways this can happen.
Possibility one is that red-green has failed to generate the needed tempo advantage early on against a deck with more expensive and therefore more powerful cards. A long game against a deck with such cards as Fact or Fiction and Prophetic Bolt seems hopeless, as the deck is simply outclassed if it hasn't already won. The tools remaining are the burn and huge monsters. If a kicked Kavu Titan or Skizzik slips through the cracks, it can do some serious damage, and often the opponent is low enough that he becomes vulnerable to burn if the kill isn't delivered quickly. Aiding in this is Keldon Necropolis, setting up an interesting dilemma in many matchups. Without the Necropolis, the red-green deck is the beatdown and the other deck is the control deck. But if the control deck doesn't win fast enough, a Necropolis can turn the tables back again. Adding two points of uncounterable colorless damage to each creature can mean that the red-green deck will win the exhaustion war if it is left to make maximal use of all its resources, although this is not the kind of matchup where that happens most often. At any rate, the goal of a red-green deck against heavy control decks is to force the opponent to tap out, exposing him to Skizzik and Kavu Titan.
How can red-green defend against this type of matchup? Lightning fast speed is one way, and against pure control both the best way and the only way. Against Domain, all that can be done is tune for pure speed and add in what enchantment removal is available. Kavu Chameleon isn't what it used to be against multicolored control decks because of Prophetic Bolt. The start of Thornscape Familiar and Raging Kavu scares the hell out of me because of Fire/Ice. Then again, there are versions that are trying to attack as well as play more expensive cards. Any deck with (for example) Gaea's Skyfolk in it is potentially vulnerable to an exhaustion strategy after sideboarding, as will be dealt with under The Solution.
Possibility two is that there is a battle against a deck like The Solution. The Solution has managed to defend itself early on and now seems to sit pretty, with Meddling Mage on Thornscape Battlemage and Excludes ready while Spectral Lynx holds off the attacking army and Voice of All delivers the beatdown. red-green now much settle into a card-exhaustion war, which is something it can win much more often than it would normally be expected to. With a Necropolis out, red-green has the more powerful cards in this matchup! This means that The Solution has to win before the Necropolis is allowed to finish its work. red-green also has the bigger creatures, forcing The Solution to line its counters up properly or die to them. After sideboarding, Crimson Acolyte must be dealt with as well.
The key here if they pursue this strategy is to turn the tables on them. Sideboard in more big creatures, particularly Kavu Chameleon to get around Spectral Lynx and the counters but also consider Shivan Wurm and Jade Leech. Even Dodecapod can work wonders. The Solution is stuck using bears as its creatures, and an avalanche of fat will bury them. The Meddling Mages are too busy stopping the Thornscape Battlemages and other removal. Crimson Acolyte may stop the red removal, but it makes the power problem even worse. Thus the answer is to sideboard out red creatures and removal such as Raging Kavu and Urza's Rage in order to bring in bigger creatures. Let them take control of the game and promptly take it right back. Scorching Lava stays because it can remove Spectral Lynx and is perfectly sized for the problem. The answer I found for The Solution was to use Lashknife Barrier instead of Crimson Acolyte. This allows Solution's smaller creatures to fight against Kavu Chameleons and their kin without making unfavorable trades, nullifies or weakens the Necropolis in creature fights, takes out Thornscape Battlemage as a removal card and makes red-green unable to trade off its two drops. For now, that's not conventional wisdom.
Possibility three is that the deck is caught in a mirror matchup or against another quick beatdown deck, in which case the goal again becomes to seize long term control through the use of bigger creatures. If Prophetic Bolt is out of picture, Kavu Chameleon starts to look really good. It's important not to forget that this format is all about tempo, but a great advantage of red-green is that it naturally has tempo to spare. The deck needs to be on the lookout for ways to control the tempo of the game, but it also needs to watch for where it can transform itself into the control deck. Other decks are already too cluttered to do such a thing, and too concerned with getting their tempo advantage or making up for a deficit to dare playing cards like Jade Leech let alone Shivan Wurm. Obliterate is yet another option, although I would shy away from more than one to prevent it interfering with the flow of the deck.
The first recommendation I would make it that the sideboard should include the second copy of Keldon Necropolis. Sideboarding is going to make some radical alterations to the mana curve of this deck, and they need to be adjusted for. If the deck had the right amount of mana before, it no longer has enough. If that wasn't enough, the Necropolis itself is an amazing weapon in the kind of war that is being prepared for when this kind of change takes place. That's not the only place it can prove useful. For example, against Domain both more mana (to punch through Collective Restraint and recover from Global Ruin) and the Necropolis ability itself are worthwhile, although this matchup still isn't good at all.
Once that is in place, the question becomes what creatures to use. I have been told by numerous people that the mirror matchup favors Jade Leech over Shivan Wurm because it is too difficult to find creatures capable of surviving so they can be gated. This seems questionable, but a red-green deck can indeed assemble around eighteen removal spells after sideboarding. This means that to use Shivan Wurm there need to be significantly more creatures than that available to gate. There's only one way to make that happen, and that's to avoid touching any of the creatures during sideboarding. If the deck includes four copies each of Thornscape Familiar, Blurred Mongoose, Thornscape Battlemage, Kavu Titan, Skizzik, Raging Kavu and Flametonge Kavu, it will have 28 targets. Of course, the logical conclusion that leads to is that the deck is going to end up with little or no removal in it. Such a deck is not well suited to the early turns of the game, and has few tricks left in it. In addition, Skizzik is a very poor way to get out a Shivan Wurm. It seems easy to see why Shivan Wurm is passed over for Jade Leech, another poor way to get out a Shivan Wurm. Then again, a Jade Leech is very hard to kill off if it stays out of combat, so it's also a reliable one. The conclusion is still that Jade Leech is the right fatty for the job.
Lucas Hager used one Tinder Farm in his version of the deck, and I think it makes a lot of sense. Many games the deck will need its mana for one big burst, for a Ghitu Fire (kicked Rage?), or for a Skizzik or Kavu Titan. By using the open turn one to put out a Tinder Farm, it creates these threats a turn earlier. It also creates an early threat of Flametonge Kavu, which will often prevent plays like Meddling Mage on Thornscape Battlemage in situations where they would otherwise be valid. And of course it provides red mana in an emergency. The downside is that with five tapped lands it increases the probability that the deck will get tripped up, which is why he stopped at one copy. An argument can actually be made that the deck's mana is good enough (Skizzik is the only double red other than kicking Scorching Lava, and you generally do that once) that Tinder Farm is actually better than Shivan Oasis, but that would definitely require more testing before I could say. Still, this points to a potential new model, with the red mana requirements lessened. Raging Kavu is a great card but definitely has issues with Fire/Ice and Crimson Acolyte. Also, if enough sac lands go into the deck then plays like Shivan Wurm and the creature it gates coming down in the same turn or using a Flametonge and Battlemage together to kill a Jungle Barrier become more realistic.
In short, don't be fooled into taking a simplistic view of this deck, and don't be fooled into thinking it's just an ugly mess of threats. It is more than that, and has the potential to be even more than it is. Just because the deck seems like it is the beatdown in every matchup doesn't make it so. When the time calls to put on the face of a deck full of fat, that's what needs to be done. When it's impossible to break through for the win, the deck must be willing to sit back and wait. At the Grand Prix, I watched many players throw games away with the deck because they sacrificed too much to get damage through, and by losing the ability to counterattack with those creatures, sped up the opponent's clock by several turns. This doesn't apply against the pure control decks, but it's vital against decks like The Solution. Also note that waiting to attack will often make it much harder to generate a good blocking scheme. When the opponent lacks mass removal, sacrificing creatures to get damage through is only justified when the death of the opponent is already visible or the amount of damage is huge. What may seem at the time like a necessary desperation attack generally just ensures that the opponent can finish up the game much sooner, taking away the chance to draw into Necropolis or sufficient quantities of burn.
What changes would I make to the standard design of the deck? Aside from the possibility of Tinder Farm the maindeck is essentially untouchable. After sideboarding, the deck should be sure to go up to four copies of Flametonge Kavu and Jade Leech, after which the sideboard gets thrown open. Thunderscape Battlemage is probably a good idea. With the Necropolis in the sideboard that leaves four more slots. Right now, I feel that Kavu Chameleon best fills those slots, although an argument can be made for one Obliterate. Chameleon is forgotten technology, but definitely needs to be remembered. Before I stop, I should warn that this is all based on conversation and observation and not on even one game played from the red-green side of the table since the release of Apocalypse. As usual, confirm as much as possible personally and play only what feels comfortable.