Usually, I take my time thinking about my strategy and tactics for Warhammer. Constantly tweaking my lists and try to resolve worst case scenarios in my head. Deployment, target priority, possibilities, movement etc. These are all things that I constantly consider before and during a game. Although I want to believe I plan my games quite meticulously, in reality there is phase that I didn't really care enough until recently. That is, placing the objectives on the battlefield. I think this step is as important (if not more) as any other aspect of successful competitive play.
I will mainly focus on objective placement for my Imperial Guard army. The same principles should apply to other shooty armies as well. There are a few mistakes I used to do constantly and I think most other players are subjects to these errors. "Seize ground" is a bit different to "Capture and Control" but there are few similar things you can do in both types of missions even though these principles apply more to the first one.
I want to start by describing the wrong way I used to place my objectives. Since I have a very shooty army with fairly fragile scoring units (Guardsmen) I always thought that the best way would be putting the objectives inside terrain near the table edges. This way I would be far away from the enemy so I could have enough time to blast his units to smithereens. Plus I could have the objectives close by for contesting. I soon realised that this was a very big mistake. In reality the complete opposite would be optimal for my kind of army build.
Think of this. What does a Guard army want to do:
1)Shoot at enemy units.
2)Stay out of close combat.
Now, if I place the objectives inside terrain near the table edges (and win the dice roll for choosing the deploying side) then I will pretty much have to place my units very close to them. Not much other choice there. This presents a major problem now. You see, I made my opponent's life much easier. What do I mean? If he is playing a close combat oriented army (Orks, Tyranids, BT, BA etc) then I already made all the decision for him (and in his favour).
Now all he has to do is rush forward and get in close combat with my units. In this way he is also getting close to the objectives so it's a win-win situation for him. Furthermore if the units are inside or close to terrain he can always consolidate into it after he is done massacring my troops. He will now be able to withstand the worst part of my firepower. He could even go to ground for the remainder of the game and still be on the objective. I don't have any assault elements in the army so it's going to be very hard getting rid of his units with just shooting when he is getting a 3+ cover save.
So by placing the objectives close to the table edge and inside terrain I get my units prone to assault and turn my shooting ineffective. I am also very vulnerable to infiltrators and outflankers since I give these units again an easy choice of where and how to deploy and contest my objective.
These days I am more inclined placing my objectives more towards the middle of the board and in open ground. This way I can counter the problems I described above.
Assaulting my fire line won't be such an easy decision now. If the objectives are far away from my troops then my opponent is going to have to make a choice of how to use his troops (charge or contest). By keeping a good distance (around 18'', about two turns of movement) you are forcing him to have to pick one or the other. It could even win you the game if he decides to go for assault and then doesn't have enough time to reach the objectives.
Furthermore you are making hard for him to camp the objective if it's placed away from terrain. Even if there is some terrain close enough to reach with one turn of movement in the last turn that still means he will have to withstand one to three rounds of shooting with no cover saves. And we know how devastating that can be from a potent Guard army (sometimes one Medusa shot is all what it takes).
Placing the objective far away from your deployment zone can be an issue for Guard though. It is obvious that in most cases you want to stay away and just shoot at the enemy. For this reason, it is always a good idea to have some mobile elements in the army. I use three transports for scoring units, two vendettas with meltavets and a chimera with a platoon command squad. They can both reach very far even in one turn (24'' for moving flat out with the vendettas and 12'' movement + 4'' disembark + D6'' run for the chimera unit) and are ideal for last turn contesting. They've won me more games than I can remember.
I also have four infantry squads on foot. These are more of a static element but if I mobilise them quickly enough (third of fourth turn) I can reach the objectives in time. This is where the "Move! Move! Move!" order comes into play. People seem to use "Bring it Down!" all the time but what is more important? A twin linked autocannon or being on the objectives fast enough? In some games I've managed to contest objectives that where on the other side of the board by using a measly infantry squad. Most opponents will just ignore it if you move out of the way, in the flanks. In the end, this little gambit can make all the difference. So there is no reason why a Guard army can't be mobile enough and contest objectives that are further away.
In a few words, it pays to place the objectives away from your fire line, towards the middle of the board. If they have some distance from terrain then even better. You have to include some fast moving scoring units in your army to fully utilise that but even footsloggers can do the job. Try this on your next game and you will see the difference.