Firstly, if you don't know how progressive islands work, refer to this post.

So, I made the best strategies for spending gems if you want to reach a certain node. First, I'll explain how this works:

-For each monster, there are several possible strategies with various amounts of time necessary. I'm also putting some strategies that take longer to complete than the island lasts because, if an island boost happens, the items take 2 times less time to collect, meaning you get twice as many items during those 2 days, which means you effectively get 4 days worth of items in that time, which can also be translated to 2 extra days.

-To find the strategy that suits you, think about how many times will you collect an entire pool of items in the 11 days of the island, and multiply that number with 8 hours to get the amount of total time you want on your strategy.

-I'm considering the amount of time required to get items once they are in the pool as 0.

-How the strategy works: For each quest, the strategy tells you the number of gems to spend on that quest. Note that quests which only require 1 breeding item can be completed almost instantly so they aren't included.
It also says after how much time is required to get you to this gem cost if there is no island boost, which is mainly helpful if you divide it by 8 hours to see how many times you should collect the entire pool of items after you get your first collection. Note that dividing by 8 also works if you're planning for an island boost; just make sure to collect every 4 hours instead of every 8 hours.
If you're going by every hour collection, you might see a remainder when dividing by 8(usually 4, when you get 3 gold and 2 food items without waste); that means that it's optimal to collect an incomplete pool and then gem.

-If you have any other questions, feel free to reply to this post.

Anyway, here are the strategies(assuming collection of what you can every hour):
Stake Rank 2: //pastebin .com/b63XdjC4
Stake Rank 1: //pastebin .com/t9iMe03m
Stake: //pastebin .com/ag2JWiUq
Scaraborg: //pastebin .com/JfkhXnBG
Cloud: //pastebin .com/VeGFS3Dr
Killeraptor: //pastebin .com/2zZPuRJ1

Strategies(assuming collection every 8 hours):
Stake Rank 2: //pastebin com/z5P890Dh
Stake Rank 1: //pastebin .com/FejWQrHC
Stake: //pastebin .com/j3ZZc398
Scaraborg: //pastebin .com/WJ89n9db
Cloud: //pastebin .com/whh2UQZK
Killeraptor: /pastebin .com/WnKWP1uZ

EDIT: per forum rules, live links removed.

Hope you dont mind Dorijan

New and hopefully improved

Thanks SO much! These are incredibly helpful posts for island events. Keep up the great work

As an IE/math guy, I’m curious what method did you use to generate these?

@BaxAttacks I use the following 2 C++ programs:
https:/ideonedotcom/KRsFYL(input is number of nodes, for each node number of gold, food, fight, breed, hatch, gems at the beginning, method for gem cost for each of these items(in this island everything was "1 1 13 3 3", but in some progressive islands values are a bit different) and 0 if you can collect the pool as soon as the mission starts or 1 if you can't(useful if i'm making custom advice for people who have already progressed), output is the number of nodes again and for each node it gives a few lines of form "'days' 'hours' 'minutes' 'gem cost'")
https:/ideonedotcom/SqRb1O(takes the previous program's output and time of the progressive islands and generates what is presented in the main post)

Thanks for posting! I'm relatively new to ML and haven't seriously made a run at a progressive island yet, but Stake is very tempting so I want to understand the algorithms and costs better. Before deciding to push for it or not, can you confirm I'm understanding this all correctly.

If one's goal was to win Stake out of this progressive island (not ranked), if one was perfectly efficient in their collections, it would take 22.2 days (adding up the red hours in your image). Using the calculated strategy, it becomes theoretically possible to get Stake in 12.7 days utilizing 1,141 gems (assuming there's bonus island time that gives us the "~13 days"). Given collecting is unlikely to be perfectly timed and efficient, it's more likely to cost someone 1200-1500 gems.

So am I correct that if one wants Stake through this island, they should be budgeting 1200-1500 gems and efficiently collecting, especially if we get 'bonus island' time?

@MUD First, I'd like to mention that the image is by Marriane, not me.

Second, "island boost" is an event that lasts for 2 days when you collect every 4 hours instead of every 8 hours, meaning you get 12 collections instead of 6(assuming you collect perfectly), which is up to 6 bonus collections.

So, if you utilize the island boost and collect every 8 hours(or, as mentioned above, 4 hours during island boost), you should be able to get Stake for 1200-1500 gems, just like you said.

I'll also edit a bit about "how the strategy works" to hopefully make it more clear.

@MUD it doesn't worth it to spend all your time and 1200-1500 gems to get a monster. Not to mention it is not ranked. The monster will be on sale a few months later for about 300 gems. If you are patient, you can also buy 20 cells with 28 gems during cell week, meaning the monster will only cost 28 * 5 = 140 gems.