Ray Allen, shooting over Lamar Odom of the Lakers in Game One, led the Celtics in scoring in Game Three with 25 points, including five 3-pointers.

AP / Elise Amendola

LOS ANGELES — There are always reasons for Ray Allen’s deliberate, finicky, if not odd, ways.

He’s always dressed in designer clothes, before and after games. He pauses slightly and then answers questions that come his way from hungry reporters on a daily basis during these NBA playoffs. He never seems to lose his cool and doesn’t leave anything to chance.

Much has been made of Allen’s preparation before games. He’s the first Boston Celtics player to step on the court before games, home or away. He’ll be launching his sweet jump shot three hours before games, getting a feel for the court, the background, everything.

This fastidious routine came in handy Tuesday night at the Staples Center. Allen prepared for Game Three of the NBA Finals like he always does, getting to the arena early and firing up shots. He quickly noticed a curveball that could buckle the knees of many pro shooting guards.

“I just made the assessment that when I was shooting in the corners, the lights are real bright,” he said. “When I followed the arc of my ball, I was looking into the lights, so it kind of blinds you out. That’s why I get to the gym as early as I do so I can adjust, but it didn’t affect me at all. It’s just a different nuance to this building.”

The glare certainly didn’t bother Allen. He led the Celtics in scoring with 25 points, including five 3-pointers, but that wasn’t enough to prevent an 87-81 Boston loss to the Los Angeles Lakers. A pivotal Game Four is tonight, with Boston leading the series, 2-1.

Allen all but carried the Celtics’ offense, and he’s leading the team in scoring in this series with a 20.3 average. After struggling badly in playoff wins over Atlanta and Cleveland, Allen found his stroke in the Eastern Conference finals against the Detroit Pistons. Talk that Allen had lost a step or wasn’t the same supreme scorer that he was with the Seattle SuperSonics now seems foolhardy. So was chatter that the Celtics’ so-called Big Three actually should be measured as a Two-and-a-Half.

“I guess Ray had to shake the jitters off because he hasn’t been in the playoffs for a while,” teammate James Posey said with a laugh. “That’s how I look at it. Now he’s got his groove back, his rhythm. Ray’s a shooter. He’s going to keep shooting. Even the shots he missed you thought they’d go in because he can just shoot the ball.”

As Allen has shown in this series, he can carry the Celtics during lean moments. Kevin Garnett and Paul Pierce, the team’s other two leaders, combined to shoot 8-for-35 in Game Three. The duo reached the free-throw line a mere five times. Those numbers must change dramatically, no matter how well Allen is shooting the ball.

“It would have been a great one to steal because I didn’t feel as if we played well all game,” said Allen. “Now we know those two guys who will step up and be there for us again.”

Allen says he’s not worried about Garnett or Pierce, and isn’t counting on scoring 25 points again tonight. Each game is a different entity, he says.

“I don’t think anything changed just because we lost a game. The series always flip-flops from one game to the next,” he said. “We never changed our mentality or even how we play, how we want to play. I think that there are things that we can do, but we’re still not going to change how we play.”

The Celtics practiced at Staples yesterday and made sure to emphasize a few offensive keys. The biggest is to cut down on a reliance of jump shots, especially early in the game. Going strong to the basket helps the team in so many ways. It’s a major strength of Pierce’s, for example, and Garnett is adept at finding cutters or scoring in the low post when he’s on the attack. It also promotes the foul issue for the Lakers and a steady diet of free throws for the Celtics.

“We’ve got to get Kevin going, clearly. He’s shooting below 40 (percent) in the series, and that’s something he doesn’t do,” said Doc Rivers. “Paul, I honestly never worry about a lot offensively. He’s a great offensive player. He had a tough night (but) he’ll get it going.”

Allen won’t be changing his preparation tactics, either. He intends on getting to the Staples Center early once again, studying the lighting, the yellow seats in the distance and plenty of game film.

“I’m just going to do what I always do,” Allen says, “but winning games is the ultimate objective. Whatever I need to do to help the team win.”

Next Game

Tonight

at Los Angeles

9 p.m.

kmcnamar@projo.com