Pardon the short, short recap, but other than Beno Udrih transforming from a turnover machine to a brilliant scorer at halftime, there's only one way to explain the massive change of course: a huge rotation switch.
In the second half, Donte Greene, Beno, Carl Landry, Dominic McGuire, Ime Udoka, Jason Thompson and Sean May basically played all the team's minutes. Only three minutes of Spencer Hawes. No Francisco Garcia. No Andres Nocioni. No Omri Casspi.
In the first half, Hawes had one point and two rebounds. In the second half, Thompson had 8/4 and May had 5/4. In the first half, Garcia, Casspi and Nocioni combined for two points on 12 FGAs. In the second half, Greene, Udoka and McGuire combined for eight points on 12 FGAs. (The Show went 1-6 in the fourth.)
Eight points on 12 FGAs is not good ... but it's better than two points on 12 FGAs. And inarguably, the second half trio is better defensively than the first half trio. (Not to say the first half trio is terrible defensively; McGuire and Udoka are only in the league for their defense, and Greene's on the floor for defense and three-point shooting.)
Ergo, Boston scored 57 points in 51 possessions (1.11 ppp) in the first half, and 37 points in 46 possessions in the second half (0.80 ppp). The Celtics rotation didn't change dramatically between the halves -- basically, Marquis Daniels replaced Nate Robinson. The Kings just did a better job stopping Boston. (The box score agrees, as the two Celtics who played worse in the second half were Ray Allen and Rajon Rondo, cats the swingmen helped on.)
And given that the team improved offensively in the process, it tells you something about the talent pool at this point of the season. The team improved when minimum-contract 30-something Udoka and trade-throw-in-sub-$2-million-free-agent-to-be McGuire replaced the burnt-out rookie and the $6-million bench swingman. This is not a slap at Casspi -- he's clearly and understandably exhausted -- or Garcia -- who's still in his December, basically, due to the injury. It's just how things are right now. Cheers to Paul Westphal for pushing for the win at the expensive of mintues for the rook and the most ballyhooed, expensive bench players.
Oh, also, Carl Landry does not give a crap about your defense. He wants the ball, and he's going to score.