Lapses on defense lead to frustration

Last season, team defense played a key role in the Clippers’ best season in franchise history.

The Clippers finished fourth in opponent field-goal percentage at 43.5%, and were 27-1 when holding an opponent under 40% shooting.

They haven’t fared as well on defense in a disappointing 10-12 start this season.

The Clippers rank 22nd in the NBA in opponent field-goal percentage at 46.2%. Mistakes in defensive rotations have often led to uncontested shots for opponents and headaches for Coach Mike Dunleavy.

“For us, it starts on the defensive end of the floor,” Dunleavy said. “Until we get our defensive numbers back to where they need to be, you’re not going to have a chance to win.

“You’ll be in games where you play well enough offensively, but you’re not going to come out of it with a win. Each guy has got to take it into their own account, as far as what they can do better.”

In the Clippers’ current three-game losing streak, opponents are shooting better than 51% from the field. The Clippers have been outscored by an average of 17 points a game.

Despite shooting 58.8% Friday, the Clippers lost, 109-99, to the Portland Trail Blazers and dropped to 1-8 on the road.

Dunleavy emphasizes defense in practice even more than he did last season, so the team’s poor performance is on the players, forward Elton Brand said.

“When you shoot nearly 60% from the field and you still lose the game ... that’s ridiculous,” Brand said. “We’ll continue to watch a lot of tape, and we’ll have to continue to grow, because Coach is going to play the guys who run the coverages and run the defensive sets right.”

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TODAY

vs. Houston, 12:30 p.m., Channel 5

Site -- Staples Center.

Radio -- 830.

Records -- Clippers 10-12, Rockets 14-9.

Record vs. Rockets (2005-06) -- 2-2.

Update -- Sam Cassell and Corey Maggette might not play because of injuries. Houston has lost three in a row -- including Friday in double overtime to the Lakers -- since Tracy McGrady (back spasms) has been sidelined. Yao Ming is averaging 26.5 points, 9.9 rebounds and 2.3 blocked shots. The 7-foot-6, 310-pound center had 35 points, 15 rebounds and eight blocks against the Lakers.

jason.reid@latimes.com