It’s common for fans to gripe about coaches – even more common than griping about ownership or players. Coaches are the most visible members of the front office, down on the floor, managing the game. This is especially true  in basketball, the most fan-friendly sport. So to some degree, it’s no surprise that C’s fans enjoy criticizing Boston Celtics Head Coach Doc Rivers.

After all, Boston’s other coaches are hardly immune from criticism. Red Sox Manager Terry Francona earned the frequent ire of Sox bloggers, though less so since the 2007 World Series. Bruins Head Coach Claude Julien hasn’t always pleased B’s fans, especially this season. Even the Patriots’ Bill Belichick is not immune (especially when he goes for it on fourth and two).

Yet for Rivers – who’s already won a title and currently coaches the best team in town – it can sometimes seem to go over the top. After all, Doc Rivers is not just a good coach, but a great coach. He’s one of the best coaches in the NBA today, and he could finish his career as one of the greatest in Celtics and NBA history.

If that sounds superlative, let’s look at the facts:

After five years, Doc has coached the third-most number of games in Celtics history, right behind Red Auerbach and Tommy Heinsohn. He has also coached the fourth-most number of playoff games (add in KC Jones ahead of him in that category). Doc’s overall winning percentage puts him sixth in team history – and that includes the terrible season he and Paul Pierce suffered through, when they were trying to “rebuild with youth.” Take out those years and he moves up a notch, ahead of Tommy Heinsohn.

All these are just numbers, though. Doc’s greatness is more readily evident in games like the win over Miami, when his end-of-the-game coaching pushed the Celtics first to rally from behind, then to make it to overtime in extraordinarily gutsy fashion and finally to win in OT. It was also clearly evident in the 2008 NBA Finals, when Doc thoroughly outcoached Phil Jackson.

It’s all to easy to say, with any great coach, that they “only” had great players. However, it’s also important to remember that coaches don’t just draw up plays – they set the tone for their team, from top to bottom. They have to keep their stars happy, get the bench guys to accept their role, and bring along their rookies. Doc has managed this beautifully with Garnett, Allen and Pierce. It’s easy to forget now that, when the Celtics acquired these two new superstars, there was no guarantee they’d get along. Doc not only got them to work together beautifully, but had them playing under a much younger point guard in Rajon Rondo without complaint.

While all of this seemed like a given at the end of the season, everything could have imploded even with the new All-Stars.

After five years in Boston, Rivers has had to overcome challenges while enroute to great success. He became just the second NBA coach to beat Phil Jackson in the Finals – and he was still playing when Jackson had already earned a few rings as a coach. His excellent management skills have kept this team together over the years, pushing them to the playoffs last year with a star player injured. In just his tenth year of coaching, Doc has accomplished more than most coaches – even more than most Celtics coaches.

At 48, Doc Rivers should have  many more years of coaching left in him. We can only hope that most, if not all, of those years are with the Celtics. He’ll continue to rise quickly through the ranks of Celtics coaches, and likely coach future generations of Celtics to great success. There’s every reason to think that, by the time his coaching career concludes, Rivers will be considered one of the NBA’s great coaches.