Example graphic:
As a Participant:
Reward x 1.9
So if you wanted to take
1st you'd type in to the Calculator: 30 x 1.9.
Your contribution to place
1st position on the building will be
57.
If the number ends in .5, round it up the next whole number
As the Owner:
Your job is to place the amount that would be remaining once all positions are filled
1st: 57
2nd: 29 (28.5 rounded up)
3rd: 10 (9.5 rounded up)
4th: N/A
5th: N/A
Total Contributions: 96 Forge Points
Owner Contribution: 210 - 96 =
114 Forge Points
So in this example you'd be expected as the Owner to place 114 Forge Points to finish leveling it. If the 4th and 5th positions are filled for the Blueprints then you might have a couple Forge Points less to place
TL;DR below section, don't want to manually secure each position
You can Google for "FoE Arc calculator" and you should find a website that does all the calculations for you. Then it's easy enough as the contributor to use a normal calculator for Reward x 1.9, and using the website calculator when you want to secure a spot for those taking a spot on your building
Securing positions
Now this is the important part for ensuring no one gets sniped from an outsider. The point of securing a spot is to make it mathematically impossible for anyone to overtake those on the building
Instead of placing your entire contribution as the Owner, you just place the amount needed to secure the positions you want taken first. Once those are taken you then add your contribution for the next position, so on and so forth. This means if an outsider puts Forge Points on the building you haven't reduced the amount they can take the position for
(Remaining to Level / 2) - (Positions to secure)
=
if positive number, keep going. If negative, the position is already secure
= (Amount to Level / 2) - (Answer / 2)
=
Owner contribution (round up if ending in .5)
You can then check you've got the correct calculation by taking the amount to level, reducing it by the Owner contribution, and making sure the amount your donator will place is equal or higher to the remaining amount
Example calculation (Securing for 1st + 2nd):
(210 / 2) - (57 + 29) = 19
(210 / 2) - (19 / 2) = 95.5 (round up to 96)
Owner contribution to secure spots: 96
210 - 96 = 114 remaining - (57 + 29) = 28 left in the Oracle of Delphi once 1st + 2nd + Owner is placed. 1st and 2nd are secure.
Note: 1st + 2nd are always secured together. It's mathematically impossible to secure 1st without 2nd if they're both being secured at the same rate. At certain levels you may have to secure 3rd position at the same time as 1st + 2nd
If there's already a (unwanted) contributor on the building, and you need to secure a spot:
Let's pretend three separate players dumped 3 Forge Points on the building. You want to make sure they can't increase their contribution to knock off a 1.9 contributor, while also ensuring you're not paying any more than you have to.
So, the calculations then look like:
Remaining to level: 210 - 9 = 201
Securing for 1st + 2nd
(Remaining to level / 2) - (Positions to secure) + (Highest unwanted contributor x 2)
= (Amount to Level / 2) - (Answer / 2)
= Owner contribution
(201 / 2) - (57 + 29) + (3 x 2) = 20.5
= (201 / 2) - (20.5 / 2)
= 90 (Owner Contribution)
In this example once you've fully filled the building you'll have paid 105 Forge Points instead of the original estimate of 114