LOS ANGELES — It took a 29-point drubbing at Denver to expose a deep, dark secret simmering in Oklahoma City, a disturbing detail that puts a damper on the delirium Thunder fans have enjoyed all season. What was revealed in Wednesday’s loss, the worst of the season, was the latest bit of evidence that illustrated just where the Thunder ranks in the NBA hierarchy. For all its quantum leaps, the Thunder still struggles to beat playoff teams. For now, it’s only a troubling trend. Come mid-April, it could be a fact that flourishes into a quick first-round exit. Oklahoma City trailed by as many as 41 points against a Nuggets team it would meet in the opening round if the playoffs started today. Throughout the season, the Thunder has fared only slightly better against the rest of the conference’s postseason contenders. But that reality has become lost in the Thunder’s 36-24 record entering tonight’s road game against the Los Angeles Clippers. The Thunder is just 7-11 against current West playoff teams. And even that mark is misleading when you factor in the breaks the Thunder has caught in four of those wins. Oklahoma City secured a three-point win at San Antonio in mid-November with Manu Ginobili sitting out the entire fourth quarter. The Thunder pummeled the Nuggets in late January while Carmelo Anthony looked on from the bench in street clothes with a bum ankle. And in February, OKC pounced on a Portland team playing without Brandon Roy, Greg Oden and Joel Przybilla, then defeated a revamped Dallas squad playing its first game with Caron Butler, Brendan Haywood and DeShawn Stevenson. The Mavs have not lost since. That leaves the Thunder with three wins against Western Conference playoff teams playing at full strength — a home and away win against Utah and a road win at Phoenix. The Thunder has built its season on beating bad teams, assembling a 21-2 record against teams below .500. The team also has feasted on the East, going 18-6 against the opposing conference. But sift through the team’s statistics against the best West competition and you’ll find a staggering disparity in some of the Thunder’s production. OKC enters tonight’s game ranked 17th in scoring at 99.5 points per game. In its 18 games against West playoff teams, the Thunder is averaging just 95.9 points. Oklahoma City also ranks 17th in field-goal percentage at 45.6 percent. But that figure dips to 40.7 percent against the conference’s current playoff teams. The Thunder’s defense, however, hasn’t seen such a drastic drop off. Oklahoma City has allowed Western Conference playoff teams to shoot 44 percent, the same fifth-ranked percentage it’s holding opponents to on the season. And West playoff opponents’ 97.8-point average is only slightly higher than the 96.5 the Thunder yields this season. That’s why the season-high 119 points the Thunder allowed to Denver still can be chalked up to being a one-game glitch. But it would be unwise for the Thunder or the team’s fan base to write off the Nuggets’ overall dominance. Denver’s starters outscored Oklahoma City’s 76-46, including 24-5 in the decisive 31-12 third quarter. Kevin Durant was the lone starter with a made field goal in the period. No stretch this season has more clearly defined how elite teams are capable of locking down the Thunder on defense. And with 14 of the final 22 games coming against teams currently .500 or better, the Thunder will have plenty of chances to show its fans what kind of playoff series they might be in store for.