I need to have the odds of probability to find blocks between 100 and 200 or between 100 and 400 coins.
It's important for me to decide how many coins I should split into different chunks in order to get as highest efficient staking as possible.
Please help with your suggestion on this issue.
Higher inputs do indeed have a higher chance of staking than smaller ones.
But most people split their BWK to 100-200 inputs, so that they will still stake on the other inputs when one of them gets a stake.
And to awnser your last question: Yes, it is twice as likely to stake than a 100 BWK Input.
It depends on what everyone else on the network is doing, there is no more precise answer that we can give you than the one that has been given. 10 different people will tell you 10 different things they think is the most efficient, and the information that could prove any one of them right changes quite literally every block.