WALTHAM — Paul Pierce  can laugh about the dark days now. But three seasons ago, when he was captain of a team languishing through a 24-win season, it wasn’t so easy.
It was after that season, and just before the acquisitions of Ray Allen  and Kevin Garnett , that Pierce thought his marriage to the Celtics , and specifically, the Doc Rivers ‘ system, was headed for divorce.
“Early years, I was almost close to divorce but I didn’t have my pre-nup in place so I had to think twice,” Pierce joked on Monday . “It was cheaper to keep her.”
“I don’t know who that is,” Rivers said  when asked if he remembers the Paul Pierce from his first season coaching the Celtics in 2004-05. “The one here is amazing. He’s an amazing person. He’s older, he’s more mature. He’s just solid. He’s a solid player.”
But after a 2008 NBA title and a 62-win season last year, Pierce is smitten once again with the Celtics and the Rivers’ system of Ubuntu.
“Put it this way, you’ve been with a girl for five years and you break up with her,” Pierce said. ” Then you have a new girlfriend, you’ve got to get used to each other because the last girlfriend, you knew everything about her, you’ve been together for so long so you’re going to make a lot of different mistakes and have a lot of different arguments.”
Well, Pierce is one-year beyond his girlfriend analogy, meaning this is more than just a casual relationship.
“I would definitely say I’m married to the system,” Pierce said . “We have a pretty good relationship going. It started out rocky. We have our ups and downs like most relationships but you’ve got to be able to ride it out through the good and the bad.”
Through 26 games this season, Pierce is averaging just 18.1 points – his lowest output since his rookie year in 1998-99. But to Rivers’ point about Pierce’s all around game, his turnovers are down to 2.1 per game, the best rate of his career and his field goal and 3-point percentages are at career-bests, .479 and .472 respectively.
“That’s all about learning each other and that’s the same thing about Doc’s system. I was still learning. We had our bumps and now I know exactly what he wants.”
What Rivers wanted and got on Sunday night was Pierce trusting his instincts as the Celtics turned to someone who could put away the Timberwolves .
And that’s what he got as Pierce scored a game-high 29 points while hauling in seven rebounds as the Celtics pulled away, 122-104.
“He’s just a solid player,” Rivers said on Monday . “His percentages, everything is better. He’s just a more efficient basketball player and he’s a more efficient person. It’s part of the maturation process. You grow up.
“Early on, I think he was just trying to establish himself and now he’s trying to establish his legacy and I think that’s different.”