We have a foosball table at work in the gaming room, it is one of the attraction during lunch hour and after five.  There is a crowd of keen foosball player come and play everyday.  Technically speaking, foosball is a team sport.  Each side has two players, one take care of the defense and the other take care of offense.  In a foosball tournament, since the partner of a team is fixed, it is easy to tell who is stronger and who is weaker.  However at work, people come and go to the gaming room.  There are no fix teams, we just pair up with whoever in waiting in the room.  The out come of the game depends not only on how good you are, but also on who you happen to pair up with.  Now, determining the rank of each player becomes a bit tricky.  Today, finally I came up with a way to rank how the player relative to each other.  I named it the Ivy foosball scale (IFS).   Ivy is the only female foosball player among the usual gang and probably the least skillful one.  Don’t get me wrong, although she is not as strong as the others, but she is considerably much better anyone else not a usual foosball player.  We can measure the strength of other players in relative term to Ivy.  The method to use is pairing up the subject with Ivy as a team.  The strength of the subject is then measured by the number of goals he can scored playing against the others.  The scale is from 0 to 10.  It is zero if the subject score nothing, it is ten if the other team score nothing.  It is quite an though up hill battle, so most of us taking the challenge lose most of the time.  If we are fortunate enough to win the game, it would always be a close call of 4-4 shot out.