It's important to note that as usual only troops can claim objectives at the end of the game but not every model can contest. Types of units have been given points values for contesting. Troops are worth 2 and all other units are worth 1 point, including rhinos. This means that a Space Marine Tactical Squad in a Rhino parked on an objective are worth 3 points and you'll need 3 other non-troop units to contest it. You cannot simply fly in an Eldar Vyper Squadron to contest. I believe this was added so that Turn 5 Contesting would be extra-difficult.
Objectives aren't the only goal. You and your opponent have a little pow-wow before the game starts, looking at each others armies and calling out 5 units to be counted as kill points. Only those kill points will count and will be just as valuable as objectives for winning. In this last tournament I averaged holding 3 objectives and taking 4 kill points. I tended to choose 2 or 3 weak units, like Rhinos or small squads, and 2 or so units that I know will be on the brunt of my opponents spearhead, things like assault terminators, khorne berzerkers and other things I knew would be essential for the guy to be cause damage.
Kill points and objectives are worth 2 battle points each.
Additonal Battle Points are awarded by accomplishing secret missions or conditions. These were worth 1 point each and were typically like the following:
1) Have a unit fail leadership on double 6s
2) Have a unit pass leadership on double 1s
3) Run an HQ down in close combat
4) Explode a vehicle in close combat
5) Control 3 objectives at once
6) Immobilize 2 vehicles in 1 round of shooting.
I've been getting better at focusing on getting this points but they're not easy. Massacring your opponent does not give you maximum points so you've got to be careful about how and when you pummel the guy.
Having played two tournaments using this system, I've begun to develop a system or at least a philosophy behind my games. I've noticed that it is much easier to gain all the kill points than claim all of the objectives. I believe long range fire is the best way to get kill points as close-combat means you have to wade through other guys first and your units get depleted slowly. With the Tau I managed to get all 5 Kill points in 2 of the 3 games I played with them. With this in mind I made sure to build in some long range fire into my Blood Angels list. I took 2 Baal Predators, a Doomhammer Land Raider and a lascannon in my tactical squad.
I've also found that opponents tend to deploy in a long line across their deployment zone. My basic game plan went in accordance to that. I would set up in a corner and either hold if it is an army that comes to me (Chaos, Orks) and fire only to unleash devastating assaults at the right moment or to move out on the attack if it is an army that is sitting still (Guard, Tau). I generally put my mechanized troops squads in reserve to move on to claim objectives as they arrived. See the diagram below.
Of course, no plan survives contact with the enemy so you've got to adapt as you go. In a few cases, I found myself ditching an objective in order for those troops to assault and get 2 kill points instead. Other times, I had my fast-moving rhinos coming in from reserve to claim the center objective and the two closest ones, or the center objective and the two on the left side of the board.
That's the 5 by 5 system. It's an alright system and allows for tactical play. I'd like to see it changed slightly. I'd like to be able to place objectives before the game starts, not have the organizers do it. I'd also like to see the deployment change from game to game. This scenario so far has always been pitched battle, 12 inch deployment. I'd also like to see the scenario get progressively more difficult as the day goes on.
That said, there is something to keeping the scenario the same throughout the day. As you the day goes on you get a little fatigued and a little warhammered. Maybe its best to keep it simple!