Trevor Ariza has been the Rockets' most vital player

The Houston Rockets have played 13 games so far this postseason, which is roughly equivalent to one-sixth of the regular season. There's not enough data to make definitive conclusions about most things, but here are two key points we know so far: Trevor Ariza is the Rockets' most important player, and Terrence Jones and Josh Smith should rarely, if ever, play together.

That second fact is particularly distressing considering Dwight Howard -- the Rockets' defensive linchpin -- is questionable for Game 2 with a strained left knee. But let's touch on that later. Let's start with the Rockets' small forward.

It might surprise you to know the Rockets actually have a negative net rating so far in these playoffs (-1.1). They're scoring 105.8 points per 100 possessions and allowing 106.7, according to NBA.com. Those are both middling regular season numbers, but not the kind of thing you expect from a Western Conference Finals team.

Dig a little deeper, and you see just where the Rockets would be without Ariza: home. The Rockets defense collapses with him off the court, giving other teams 113.1 points per 100. The team's net rating is 1.4 with him on the court -- a team high -- and -10.6 when he's off, a team low. In fact, just three Rockets, him, Dwight Howard and Josh Smith, have positive net ratings. That's not great.

This isn't a massive surprise, but it is startling to see that Ariza, statistically speaking, is a more important player to the Rockets in the playoffs than James Harden is so far. Ariza's been great on defense: he's allowing 0.69 points per possession when guarding the pick-and-roll ball handler and 0.82 PPP when guarding the handoff, just as examples.

But he's also the Rockets' best catch-and-shoot player, hitting on better than 41 percent of those attempts so far -- a crucial number considering how often his man crashes in on Harden drives. He's leading the league in spot-up attempts in the playoffs so far, and he's scoring 1.27 points per possession when he's spotting up, a terrific number.

Leaving statistics aside for a minute, Ariza looked lost at the beginning of the conference semifinals. He was pump-faking on three-pointers and settling for mid-range jumpers. He looked so uncomfortable with the ball it was hard not to wonder if the moment had gotten to him.

In Game 4, something clicked with Trevor and he rediscovered Athreeza. Since the start of that game, he's shot 53.8 percent from deep, and it's come at the perfect times. He's also been able to use his length to bother Chris Paul, Blake Griffin and anyone else he's been assigned to. His hustle cannot be overstated, nor can his calming presence. He's had just one turnover in five of his last seven games.

When things tend to go awry for the Rockets are the times when Ariza sits. Slot Corey Brewer in his spot with Smoove at the four, Harden at the 2, Howard at the 5 and Jason Terry at the point, and the Rockets give up 121.3 points per 100 possessions.

The lineup data is where it becomes painfully clear that no matter how good Ariza is, the Rockets just aren't good with Smith and Jones share the floor. With Smith at the 5, Jones at the 4 and the starting wings and point, the Rockets are being outscored by 43.6 points per 100 possessions. 43.6!

It doesn't matter who's on the court, the two power forwards can't compete together at both ends. In the 41 minutes they've shared the floor, the Rockets' offensive rating is 101.8 (good not great) and the defensive rating is 129.5 (an outright tire fire).

In a stunning turn of events, Clint Capela has become an important bench cog, and he should be playing over Jones more at this point. He's a fluid runner, a terrific leaper, has shockingly great hands and an impressive feel for the game. When he and Josh Smith are on the floor, the Rockets are outscoring opponents by 4.3 points per 100 possessions. He and Jones have been bad together in their 29 shared minutes on the floor, but not as bad as Jones and Smoove.

The Warriors' best lineup is Stephen Curry, Klay Thompson, Andre Iguodala, Harrison Barnes at the 4 and Draymond Green at center. They have absurd floor-spacing with this group, as well as the ability to switch pick-and-rolls 1 through 5 and everyone can handle the ball a little bit. Solving this lineup is the key for McHale to solve this series.

The Rockets have their own funky brand of length they can put on the floor, with Harden, Brewer, Ariza, Smith and Capela or Howard. When Harden, Brewer, Ariza and Pablo Prigioni share a floor with a big man, they have four guys who have a nose for creating turnovers and score 129 points per possession by living in transition.

Ariza, Brewer, Harden and J-Smoove have only shared the floor together for 20 minutes this postseason, and are scoring 1.5 points per possession -- the equivalent of shooting 50 percent from three-point range every time down the floor. With the way Ariza is playing, and the way Smoove and Jones are faltering when they play together, McHale should try experimenting more with Capela and Smoove, just Capela, or just Smoove.

Against the Warriors, the status quo just might not be enough.