However, the probability of successfully staking under POS also depends on the amount of coins you have. However, some coins have a dPOS algo that allows you to delegate your stake to another party, or you can also pool your stake with other coins.
Lisk and EOS are examples of dPOS coins, while NEO, Gridcoin, Blackcoin and Peercoin are some examples of POS coins.
Oh, I do not understand clearly here. I think the reward of staking should be equally divided for the stakers.
For example:
total coin: 2000, annual inflation = 1%
=> Each year has 2000*1% = 20 new coin created.
If there are only 2 stakers:
A with 100 coin in his wallet
B with 900 coin in his wallet
=> Then the reward will be divided for the stakers as below:
A = 20 * (100/(100+900)) = 2 coin
B = 20 * (900/(100+900)) = 18 coin.
Right?
Some PoS algos may differ, but in general, PoS is similar to a "lottery" concept.
To simplify an explanation:
In your example, the total staking pool is 1000 coins (100+900).
For every block, A has a 10% chance of staking a block while B has a 90% chance due to their staking balance. On average, A will get the block reward for 1 block out of every 10 blocks while B will get the block reward for 9 blocks.
This is different from what you mentioned about the stake rewards being divided equally because in the practical sense, if there was a third staker with 0.0000001 coins, it does not mean that he will get a proportionately small block reward for every block. It means that he may have to wait a very long time before he successfully stakes a block.
Probably a way for a very small staker to get rewards will be to join a staking pool, but even then there will probably be a minimum withdrawal amount so it might still take a long time to see any real rewards!