BOSTON — The homestretch of this season is upon the Celtics (22-41) as they stare down what should be their final 19 games of the season.

But before we get too knee-deep in the upcoming NBA draft and free agency and trades and all the things that fans of losing teams look forward to, let's take a moment to embrace this season for what it truly was.

This season was about lessons learned.

For fans, there was a greater sense of appreciation for the success of the Big Three era now that it's over, and the promise that the Celtics' youngsters have shown throughout the course of this roller coaster of a season.

For rookie head coach Brad Stevens, it was getting a feel for the nuances of the NBA game while enduring more losses before Christmas than he had in any individual season at Butler.

And last but certainly not least, we have the players. They too have been in class all season, absorbing both the blows from opponents and the benefits that come with experience.

It has made for an entertaining season even if the win total wasn't nearly as high as this franchise has come to expect. And while it is impossible to look at this team and not think about the future, there's value in acknowledging where they are now.

With that, here are the third quarter grades for the Celtics.

Rajon Rondo
Has re-established himself as the best player on this team, even if's not up to playing in back-to-back games yet. His 18-assist night without a turnover against Detroit ranks as one of his best regular season performances ever.

Kelly Olynyk
Has played some tremendous basketball recently, averaging 16.7 points and six rebounds while shooting 58.6 percent from the field in the last three games.

Kris Humphries
Arguably the most consistent Celtic this season, Humphries' defense, rebounding and shot-blocking skills have been a pleasant surprise to Boston.

Gerald Wallace
His numbers won't wow you, but there's no denying the value in his veteran leadership prior to having season-ending knee and ankle surgery this month. Wallace holding himself as well as teammates accountable for their play was vital to Boston being a competitive bunch all season.

Jeff Green
Often criticized for not being aggressive or consistent enough, Green has kept his critics mum with a series of strong performances lately.

Brandon Bass
Has been a surprisingly solid defender this season, showcasing a more all-around game since the departures of Kevin Garnett and Paul Pierce.

Jared Sullinger
His emergence as their best rebounder despite playing the season with injuries to both hands, bodes well for his chances of being a difference-maker when fully healthy.

Avery Bradley
Despite missing games with a sprained ankle, the evolution of his perimeter game has been impressive.

Jarryd Bayless
Gaining a better feel of how to play well both on and off the ball with the Celtics.

Chris Johnson
High energy player, needs to develop more to his game other than the three-point shot.

Phil Pressey
At his best when pushing the ball, has good court vision and sticky hands defensively.

Vitor Faverani
Sad to see his season end due to an injury, but even when healthy he was falling off the depth chart.

Chris Babb
The newest guy to the team, will be around after agreeing to a second, 10-day contract.

Joel Anthony
Hasn't been given much of a chance, but to his credit has stayed ready when called upon.

Keith Bogans
A Celtic in name -- and contract -- only.