It's official: Cole Hamels and the Phillies have agreed on a six-year, $144-million contract extension that may keep Hamels with the franchise through at least 2018.

From 2008 through today, here are the five best National League pitchers, measured by Wins Above Replacement:

Clayton Kershaw
Tim Lincecum
Josh Johnson
Cole Hamels
Matt Cain

Considering Lincecum's struggles and Johnson's various injuries, you might certainly argue that Hamels is one of the league's three best starters in his 20s, with Stephen Strasburg joining that group once he's pitched long enough to prove he's completely healthy for a while.

In the press conference, Hamels said a great deal about how much he loves the game, and the fans in Philadelphia; it was those fans, more than anything else, that made him want to stay with the Phillies.*

* Sorry about the lack of quotes, but Hamels mangles grammar to the point where I couldn't really find a quote that I thought you would want to read.

Obviously, $24 million per season is a great deal of money. That's the going rate these days for premier pitchers these days, though. The riskier figure is six years; as we've seen so many times, there just aren't many pitchers who can stay healthy for six seasons. On the other hand, Hamels has already been healthy for roughly seven seasons. Does that mean he's significantly more likely to make it through another six without a serious problem?

That's a good question.

When Ruben Amaro Jr. was asked what made him "comfortable" going six years on Hamels' contract, he smiled and said, "I don't know if I'll ever be comfortable, but we felt like it was the right thing to do under the circumstance, with his performance, his age, the importance on our club ... Our goal is to try to continue to be a championship-caliber team for now, and for the future. And so, as I said before, and I've said it publicly, several times, we have a much better chance with Cole in our rotation, and as a major part of our club, than without him."

Which is true, in the abstract. And maybe the Phillies' financial resources are functionally limitless. When they committed so much money to Roy Halladay and Cliff Lee and Ryan Howard, there was much speculation that they wouldn't be able to pay Cole Hamels what it would take to keep him.

But now they have.