The RTP (Return to the player) of a game is calculated over millions of spins from all customers, you can find the RTP within each game description or game rules. Each spin is independent of those that came before and any subsequent spins. Each game is run by a random number generator which is built into the game to randomly decide who wins when and how much and nobody can affect the game without fundamentally changing the game and rethinking it. Therefore, anyone can play one round and win one million while others can play thousands of rounds and not receive anything in return. 

Each spin is unique to the former and does not take into account any personal factors.