Champions 2020 has the same main mechanisms as StreetSoccer, which was published in 2002. Both games were developed in parallel over a thirty-year period. Why is the game set in 2020? A few soccer rules changed by that year, making the game more fluid.
While StreetSoccer simulates soccer with five players on a side on a small square, Champions 2020 simulates stadium soccer, so the field is bigger. As coach you select 11 players as a starting line-up (goalie, defenders, midfielders, forwards), while the rest of your team starts in the dug-out for possible substitutes (after warming up).
Your professional soccer players are more skilled than street soccer players, which leads to spectacular stadium matches. Players can try to hit passing balls, which can lead to throw-ins, corner-kicks and goalie-kicks. As skilled team players, your players can anticipate on passes. Your goalie is skilled, too. With good positioning he has the best save chances, which depends on the speed of the shot and the distance to the ball. A rebound is possible, but a better save is catching the ball in his hands.
Unfortunately, the players are "skilled" in causing fouls (or "schwalbes"), too. As soccer coach, you can't always control your players – and that leads to free kicks, penalty kicks, yellow/red cards and injuries.
For tournaments the yellow/red cards, injuries, extra time, penalty kicks and stats make the soccer simulation complete.