The 2020 Western Conference playoffs were defined by the lineup decisions coaches were willing, or in one notable case, unwilling, to make. When the Los Angeles Lakers lost Game 1 of their first two postseason series, Frank Vogel was willing to make the drastic changes necessary to right the course. He abandoned his centers against the Rockets and moved Alex Caruso into the starting lineup against Miami to win the championship, but his Los Angeles counterpart wasn't willing to make the hard decisions when they were necessary. Doc Rivers stuck with Montrezl Harrell until the bitter end, and as a result, the Clippers were knocked out before their long-awaited matchup with the Lakers could even happen.

It's an instructive example for the coaches of this season's Western Conference contenders to follow. Land on the right units and you can win the title. Stick with the wrong ones and you won't. We covered the most important Eastern Conference lineups earlier in the week. Here are the most important units for each of the top four West contenders entering the postseason.

Los Angeles Lakers

Swap Marc Gasol in for Drummond and the unit above blasted opponents by 13.9 points per 100 possessions before Davis got hurt. The theory of the lineup was sound: space the floor properly for the James-Davis pick-and-roll and your offense effectively becomes unguardable. Davis masked Gasol's physical deficiencies. Gasol provided supplementary playmaking. Schroder provided supplementary ball handling. Every box was checked. 

The Lakers know the consequences of poor spacing in a James-Davis starting lineup well. They lived it last season with JaVale McGee. Why they chose to go back to it with Drummond is a subject of intense debate, but we've long passed the point of discussion. Drummond is going to be the starting center entering the postseason. Yes, the Lakers will move Davis to center when they have to, and yes, Vogel is open-minded about lineups, but the margin of error is thin here. Imagine a scenario in which the Lakers face the Clippers in the first round. If it takes them two games to realize this unit doesn't work, they might be down 2-0 to a team fully capable of beating them.

James hasn't yet played with this group yet, but the early returns on the Davis-Drummond pairing have been discouraging. In 83 minutes together, they've been outscored by 26 points, and their defensive rating of 119.2 is the second-worst of any two-man Lakers combination that has played that many minutes. With Drummond on the floor, Davis turns into a jump-shooter, and if he doesn't maintain the Kevin Durant-like efficiency of his 2020 postseason run, that minimizes his value. 

Things will click back into place once LeBron returns because... well... it's LeBron. He won't tolerate Drummond's low-post shenanigans or inconsistent defensive effort. He'll weaponize Drummond's size in the pick-and-roll, and Drummond's rebounding should help ignite the transition offense that the Lakers relied so heavily upon last season. 

But it should be lost on no one that the Lakers had the best starting lineup in basketball and willingly discarded it to get to this point. This unit can't just make sense to justify its existence. It has to thrive, and if it doesn't, Vogel needs to recognize that quickly and pull the plug. That's easier said than done. Promises were no doubt made to recruit Drummond in the first place. He's a 27-year-old impending free agent. He wants to play. So does Gasol. So does Montrezl Harrell (whose place in the rotation, given his defensive issues, should be subject to more scrutiny). This is a politically fraught situation, and it's going to take deft management to handle it. 

Utah Jazz

The trouble with picking a single lineup as Utah's most important is that basically everything the Jazz have tried this season has worked. They have 11 different lineups that have outscored opponents by at least 20 points. The Lakers and Clippers have 10... combined. Utah's formula is so simple and transferable across different players that basically any combination of their top players is going to yield similar results. Elite rim protection and perfect shot selection are almost always a recipe for success.

The question for the Jazz then becomes how far they're willing to deviate from that formula when matchups call for it. Utah broke up the Gobert-Favors duo in 2019 specifically intending to reach this point. They now lead the NBA in 3-point attempt rate largely because they were willing to downsize. Favors and Gobert played 739 minutes together during the 2018-19 season. This season? They've shared the court for only 20. The Jazz have outgrown bully ball.

But winning four rounds demands versatility, and the Jazz know that. You don't spend $27 million on a backup center without expecting something bigger out of him down the line. The bracket might deliver only small-ball foes. It might also draw the Jazz the Lakers in the second round, or the 76ers in the Finals, and when that time comes, the Jazz will be fortunate that they at least have this card in their back pocket, should they need it. 

Joel Embiid blasted Gobert for 40 points the last time they met. Nikola Jokic and Anthony Davis have had similar success against him. But more pressingly, their teams have as well. Gobert is wasted as a pure post defender. Favors offers an alternative: let him bare-knuckle brawl opposing stars in the post while Gobert nominally guards the weakest opposing shooter, but really slinks back into his rim-protecting role. It's not a 30-minute solution, especially when those opponents put their best lineups on the floor to match Utah's, but it's a look the Jazz have at the ready if needed. The only question is whether Quin Snyder will be willing to abandon the unstoppable identity his team has spent all season developing.

Los Angeles Clippers

If the 2020-21 Clippers maintain their current efficiency, they will go down as the greatest jump-shooting team in NBA history. The only other team to shoot 41.6 percent from behind the arc in a season without a shortened 3-point line is the 2015-16 Golden State Warriors, who did so on lower volume. They beat those Warriors in the mid-range as well, 44 percent to 43.4 on higher volume. They have the NBA's best 3-point percentage above the break and in the corners. Rajon Rondo has added sorely needed shot-creation. Reggie Jackson and Terance Mann are (finally!) starting to generate shots at the basket. But this is a team that will win or lose the championship based on its jump-shooting.

Morris at the five is their death lineup. The Clippers have played 396 possessions with Morris at center this season. That's not a sustainable sample size, but it's not a tiny one either. In that time, according to Cleaning the Glass, they've scored 138.4 points per 100 possessions.

Hang on. Take a deep breath. Go collect yourself. Ready to continue? Good. 

I reiterate: the Clippers have scored 138.4 points per 100 possessions with Morris at center this season. Here's some perspective on that: the actual death lineup, even after it added Durant in 2017, scored 126.9 points per 100 possessions in 476 total possessions. That's a gap of 11.5 points per 100, bigger than the 10.7-point gap between the No. 1 ranked Nets offense and the No. 27 ranked Pistons offense this season. Again, we are dealing with small and unsustainable samples here, but these numbers are so preposterous that they can't be ignored entirely. The Clippers, as a team, have an effective field goal percentage of 63.9 percent in these minutes. Only six players in NBA history have ever matched that feat over a full season (on at least 10 shot attempts per game). The average Clippers field goal with Morris at center this season has been more efficient than a 2015-16 Stephen Curry shot attempt. Let that sink in.

So why aren't the Clippers going to these groups more? Defense, for starters. They've given up a ridiculous 126 points per 100 possessions. That's another unsustainable number, and it's one that should drop significantly in the small-ball-centric playoffs. Lineups featuring Morris, Kawhi Leonard and Paul George with any combination of Rondo, Mann, Patrick Beverley and Nic Batum should be able to switch comfortably against most lineups. But these groups are getting killed on the glass, and nothing is changing that. The Clippers wouldn't dare try this against Davis, James and the Lakers. They're too big. It offers far too little resistance at the rim.

But if they need to get into a track meet with the Nets, or combat Phoenix's lethal bench units? This is their trump card, an offense explosive enough to beat anybody no matter what happens on defense. 

Phoenix Suns

That plus-13.9 net rating for the original Lakers starters is strong, but hardly out of the norm for a contender. Utah's starters are in double-digits as well. The Clippers have had to shuffle so much that their true starting five is unclear, but their most-used group is plus-16.7. There's common sense to this. Most teams start their best players. The best players on the best teams should dominate. 

So why haven't Phoenix's starters? No five-man unit in all of basketball has played more minutes together than the five players listed above. Their net rating together? A pedestrian plus-4.8, dragged down largely by an underwhelming 110.8 defensive rating. The Suns have gotten by for most of the year thanks to Dario Saric-led bench units that are torching opponents by 12.4 points per 100 possessions.

Those groups will be minimized in the playoffs when rotations tighten and teams can no longer fatten up against the worst opposing players. Saric at center might not even be viable at all in certain matchups. Davis would eat him alive. If the Suns are going win the championship, their starters are going to have to be the reason why.

There are encouraging signs on that front. Their defense has improved in March and April, with more reps together under their belts. They've been the victims of some bad shooting luck as opponents have hit 39.7 percent of their 3-pointers against this lineup, specifically. Paul remains one of the NBA's foremost clutch maestros. If Phoenix can keep games close, he can win them in the end.

But Phoenix's remarkable health in a season ravaged by COVID-19 is going to create doubts here. None of their peripheral numbers paint the picture of typical champion, but they might land home-court advantage simply due to the injuries everybody else has suffered. The up-and-down performance of their starters raises further questions. Are the Suns just a great regular-season team? Or are they true contenders? The answer is going to come down to how good this fivesome can be against the best the Western Conference has to offer.