Question about how “crossover” works in gen evo

If I choose %50 crossover probability does that mean the top 6 out of 12 strategies will copulate? Which one copulates with which one? Is it rank #1 and #2 paired together and then #3 with #4 etc? Or is it #1 is paired with #6 and #2 with #4? Or is it random? Or is it #1 pairs with each of the other top 6 once?

I guess it is way more complex than that. Is there any more info regarding precisely how the gen evo works? I have read the pdf and checked out the courses included…. does the advice in the courses and pdf still apply to SQX? I have also found this post:

Mark Fric wrote:

Islands are a new feature in SQ4. Running genetic evolution on multiple islands means that there is an independent evolution run on every island, with ocassional migration of soem strategies from one island to another. Its advantage is better diversity of strategies and that genetic evolution is not stucked in one locale maximum, as each island is independent and starts with its own initial population. Its disadvantage is that you have to multiply the population by number of islands, because random initial population will be generated for every island. If you set islands=1 then it behaves as same as in SQ3. I think the reasonable number is 5-10 islands, I don’t see the point of having more than 20 islands. There is one more thing that influences the size of initial population – it is decimation coefficient. If you set it to something bigger than 1 it means it will create bigger initial population, and the best candidates are chosen. For example, your population is 10, you set decimation to 3. It will generate 3 x 10 = 30 filtered strategies, and top 10 from them will be selected as initial population, the rest will be thrown away. You can see that the number of strategies in initial population can grow quickly. If you have population=50, decimation=3, islands=10 then SQ has to generate 50 x 3 x 10 = 1500 strategies that pass the initial filter only to generate initial population.

Any other reading I can do on this topic for how it works in SQX or advice for the settings?

Crossover % is the percentage of members of the population generated from crossover. Crossover takes part of one member and combines it with part of a different member to create a new member of the population. The genetic evolution process remain the same in SQ3 and SQX