Belicheck is probably the best coach

In the history of the major four American sports. What he has accomplished in this era or parity is incredible. His accomplishments cannot be overstated.

On the other hand- this is part of the reason Tom Brady will forever be the most overrated professional athlete of all time. I can think of at least ten quarterbacks I'd take over TB if I were tasked with starting a team and could grab a QB from any era. He is a great player, but he was dealt a hand that no one else in professional sports has ever and will ever see.

Consider this, for example:

When Peyton Manning missed a year with injury, the Colts went from a team that was averaging 12.2 wins over the previous five years to 2-14.

When Tom Brady missed a year with injury, the Patriots went from a team that was averaging 13.2 wins over the previous five years to 11-5.

Belichick *is* the Patriots dynasty. Brady could've been replaced by a number of quarterbacks and they'd have done the same thing, or possibly accomplished more.