By -Netput - 19 Oct 2013

For some people numbers are the most boring things ever. However, without numbers it is hard to make the right decisions in the heat of battle. For all the people that hate number cracking, we did it for you! In this tip of the week we will investigate the oil derrick and the APA supply center.

If you want to expand, the first decision you have to make is whether you expand with oil derricks or build a whole new supply depot. Obviously this is a decision that relies heavily on the way the game is being played, but the following numbers might help you out.

Oil for everyone!

Oil derricks seem to be the easy route. They are cheap, build fast and generate a steady amount of income. The initial investment of an oil derrick is 600. Every oil derrick takes 22 seconds to build. This means you have to hold on to the oil derrick for 2 minutes and 22 seconds before it generates profit (600/5+22). Every minute the oil derrick will generate 300 for you.

Gather it yourself

Supply depots are the second way to collect resources. Investing in a supply depot is a whole different world though. They take a long time to build, but are a lot harder to harass. So are they worth it? First we need the numbers! A supply depot will cost you 1890 bucks and it takes 70 seconds to build. After your initial investment you still have to buy those precious harvesters. Each APA harvester will cost you 300 and they take 15,16 seconds to build. If you expand and you build 4 extra harvesters right away, this will cost you 3090 (1890+4*300). After 3 minutes and 24 seconds you gathered enough supply to become cost effective.

After that, the supply depot is a great structure to have though. They generate a lot more income per minute compared to an oil derrick.

We have measured the income per minute based on the amount of harvesters:

The first 4 harvesters each generate 408 income per minute. The fifth harvester will lower the effectiveness per harvester, but it still will show you an increased in income per minute. The lower income per minute can be explained by the waiting time. Each harvester has to wait to unload their cargo. Once the unload station is clear, harvesters have to accelerate again and this will cost some time.

There is absolutely no use in building 6 or more harvesters, as the supply depot seems to capped at a maximum of 1680 supply per minute.

So what are we saying?

The bottom-line of all this is that the decision is quite hard! If you are sure you can hold off your enemy, the supply depot is the way to go. If you are under constant pressure, the oil derrick is the best bet. If you compare the income rate versus the amount of money you have to spend, the supply depot and the oil derrick are pretty much equal.

The supply depot has an income rate of 1680 per minute and costs you 3090 with 5 harvesters.
The oil derrick has an income rate of 300 per minute, but only costs 600. So for 3000 you can get 5 oil derricks. Which will bring you to 1500 (5*300) income per minute.
It is up to you to decide if you can save up the money to build a supply depot, or that you should focus on building units instead.