Yeah, lost both games but both losses were nail-biters. Both games came down to the final few moments and Dallas barely managed to squeeze out the victory on both occasions. They could have just as easily lost those games as won them.
I felt like Boston usually does very well against the Mavs. I remember a couple of big wins in Dallas on road trips and holding serve at home. I looked it up, the Celtics had won 5 of the previous 6 before last season's double loss.
I thought that Rondo has caused the Mavs a huge amount of problems in the past with his quickness (Kidd is too slow) and KG is one of the few good defensive matchups in the league against Dirk. Celtics team defense used to cause them a fair bit of problems, unsettled Dallas (past tense? will this still be true this year?).
Pierce and Ray usually play well against Dallas as well. In large part due to the havoc Rondo creates with his dribble penetration, transition play and overall passing. Get a lot of good looks at the rim. I think Pierce likes playing against Dirk too due to that draft connection.