It is is a good benchmark. As a matter of fact it was built to help my hockey tournaments put together tournaments with more parity. The problem is it is relied upon as though it was accurate past whole numbers. So if you are making decisions down to the 1/100 then you have a problem. This is where the accuracy problems comes into play. If you have a team that is a 95.34 and a team that is a 95.30 and this is only measure, you have a done a disservice to accuracy. As someone already mentioned teams do not report all of their games. Then there is fact that the numbers of games played is crucial. Because if you comparing teams to make the numbers a true comparison you need the numbers of games to be the same as well. Otherwise you comparing averages. He is the kicker. If a tournament team plays a full season team their numbers stay in the calculation even though the tournament team may never have enough games to actually show up on the ranking. I will say this tends to be a bigger problem in AAA because not all of the teams in the district play each other. Which should be a requirement.