Implementing an Elo Rating System
Question
The Elo Rating System is a method for calculating the relative skill levels of players in zerosum games such as chess.
Below is a simplified description of the system for our purposes

Each player starts at the same score

For each game played, the loser transfers points to the winner, and the amount of points that are transferred depends on how likely the win is

For example, if a player is ranked 2000 and is playing against a player with a score of 1700 then the lowerranked player would receive a disproportionate amount of points from the higherranked player in the event of a win
Given this information, write code that will implement this system. The exact point differentials you allocate in this simplified system can be arbitrary, but the key is to cover the bullet points above.