Why does the 2 year Treasury yield consistently lead moves in the Federal Funds Rate?

When looking at historical charts, the 2 year yield appears to move well in advance of the Federal Funds Rate, often predicting the direction and magnitude of Fed policy with high accuracy. If the bond market is essentially "guessing" the Fed's next move, why are there so few misses? Is the market simply better at processing data than the Fed, or is there a mechanical reason why the Fed is forced to follow the market's lead?