DE reserving when going second

When going up against a shooty army that wins the roll-off, it is often better for the DE player to reserve rather then deploy. Sometimes, you might be able to find enough los block or migitate the opponents firepower enough to deal with going second on the board, but even this has drawbacks. These drawbacks are most apparent with a venomspam list, which utilises mostly blasters for antitank. 18" range blasters means that you've just committed your models on the battlefield, but will have to zoom forward from that corner you're hiding in in order to get in range. Sometimes, this really isn't worth it.

When reserving you're always gonna be fighting with about 50% of your army against the entire opposing army when you come in on t2. However, DE have so many units placed in reserve, that you can expect pretty average results. It's easier to score that 50% average with over 10 units in reserve, compared to armies with less unit choices. The main advantage in reserving vs deploying in a corner is that you are not committing any of your forces in deployment, but you'll be able to strike anywhere across the entire board edge on t2. You're keeping the initiative in the game and aren't stuck in a certain place with your weapons. You wouldn't believe how many people come withing 32" of your board edge (range of disembarking blasters), meaning that you'll be getting all your shots off, just as if you were alphastriking a poorly deployed opponent. It's a difficult situation for your opponent. If he stays outside of blaster range, that's 2 turns of movement away from him.

It's good to remember that you don't have to fully reserve your army. If you have losblock in your deployment zone, you can stack the amount of venoms/lances that you'll be getting for your t2 betastrike(?). I would deploy units that have a longer range, like ravagers. Thus, you're still able to strike pretty much anywhere on the board and aren't limiting your options on t2. Deploying troops is a little risky. By deploying them, you are commiting them to a certain point on the battlefield. In objective missions, you might want to rather have them in reserve and see where you want to have them once they come on.

So, when reserving you want to maximize the gains from it. Steal 2 shooting phases from your opponent and maintain the ability to strike anywhere along your long board edge. When you come on, it's generally better to pick off a weaker side of your opponent's battleline and try to annihilate it first.

Although DE is one of the few armies that frequently goes into reserves when going second, the same applies to any army that is looking to go full reserves.