Reflect, then look ahead

In nine January games prior to last night - all without Garnett - the Celtics were 4-5, and in four of the losses Boston blew second-half leads with poor defense.

Last night, the Celtics held Portland to 2-for-13 shooting in overtime and 17 for 49 after halftime (35 percent). Although the Celtics missed a handful of layups and short jumpers, they countered by getting stops, something that wasn’t the case without Garnett.

“It’s very difficult sitting there watching. I don’t sit on the bench for a reason,’’ said Garnett, who finished with 13 points, 4 rebounds, and 3 assists in 30 minutes. “The impact I think I can give this team is tremendous. I bring a lot of energy when it comes to defense, a semi-high IQ when it comes to defense. I look for guys, I get guys open, some of the small things I think we’ve been lacking the last couple of games.’’

During their slump, the Celtics turned into a first-half team. Their second halves were riddled with turnovers, defensive miscues, and selfish play.

Following Wednesday’s loss to the Pistons, Ray Allen and Rajon Rondo had a stern conversation, and concluded the genesis of their problems were offensive selfishness and lack of help defense. Garnett will erase many of those problems, but can’t expunge them all. That’s too much to ask.

The Celtics have to work harder defensively in fourth quarters. Portland’s Andre Miller was stellar for most of last night’s game, but he missed 4 of 5 shots in overtime and wasn’t able to get to the paint as he did in regulation. The Celtics showed a vast improvement on inside defense from Wednesday, when Detroit’s Rodney Stuckey scored 27 points with a career-high 11 rebounds.