It isn't simply the effect of having only 10 players on the pitch that determines the result. There are many other factors which influence the outcome of the game. Those factors play a part irrespective whether there are 10 or 11 players in the team. Fitness, form, tactics, state of mind etc, as well as external factors such as refereeing and managerial decisions, conditions, time left in the game etc.
Losing one player from a team of 11 is not such a significant change in the dynamic of the team as to consistently produce a different outcome when compared to playing with 11 players. So whether it is a disdavantage is subjective - just as it would be if there was a change in some other aspect of the game which might have a bearing on the outcome e.g if it was very hot, muddy pitch, injury to key player etc.
Obviously, there are times when losing a player will clearly be demonstrated to be a disadvantage, but that depends on specific factors e.g loss of goalkeeper, sending off early on hot day etc rather than general ones. There is no pattern. There is no formula which states 11-1=diasdavantage.
Losing one player from a team of 11 is not such a significant change in the dynamic of the team as to consistently produce a different outcome when compared to playing with 11 players. So whether it is a disdavantage is subjective - just as it would be if there was a change in some other aspect of the game which might have a bearing on the outcome e.g if it was very hot, muddy pitch, injury to key player etc.
Obviously, there are times when losing a player will clearly be demonstrated to be a disadvantage, but that depends on specific factors e.g loss of goalkeeper, sending off early on hot day etc rather than general ones. There is no pattern. There is no formula which states 11-1=diasdavantage.