“I just can’t watch the NBA, you know? They don’t play any defense.” Every basketball has been there. Small talk with a stranger reveals your affinity for this beautiful game, but your conversational counterpart, whom you’ve found to be pleasant up to this point, reveals his/herself to be not only shockingly ignorant about, but also perfectly willing to dump all over something you enjoy. It’s an asinine statement, and it’s almost always followed by a confession of having “not really watched any basketball since Jordan retired.” You don’t say.

At a glimpse, the casual fan might notice the inflated final scores, the pressing pace and the never before seen prevalence of the three point shot before arriving at such a conclusion. But the true hoops heads understand what a large role defense has played in determining this year’s Conference Finals competitors.

Golden State’s overwhelming talent distracts from the fact that they’re one of the league’s most capable defensive squads. Their ability on that end, and Draymond’s transcendent talent, is a big factor in their dominance. Houston, having possessed one of the league’s most potent offenses for several years now, did more than just add Chris Paul. They tweaked their roster to improve on the defensive end, understanding that more length and defensive versatility is their only shot at competing with the Warriors.

Cleveland is here because of LeBron James and for that reason alone. But LeBron is the exception to every rule. To reach the Finals, he’ll have to get through Boston—a team that might reach the finals simply because of their defense. And that was the story in game one of the Eastern Conference Finals.

Boston put on a defensive clinic on Sunday afternoon. The Celtics held the Cavaliers to 15 percent shooting from deep and 83 points overall. Al Horford was the best player on the floor and Marcus Morris had the last laugh, holding LeBron James to just 15 points. It was somewhat jarring. After having watched James wipe of the city of Toronto off the map less than a week ago, we saw Cleveland revert to the same uninspired play that almost got them booted in the first round.

Kyle Korver, Kevin Love and J.R. Smith shot a combined 2-12 from deep but the blame can’t be heaped entirely on the King’s court this time. James himself was 0-5 from three point territory and he turned it over seven times on his way to a game low -32. The Cavs were horrendous, but Boston deserves the credit. This isn’t luck—this is Brad Steven’s vision, and the Celtics defense has been doing this all season long.

Despite missing the offense of Kyrie Irving and Gordon Hayward for much of the season, the Celtics never really faltered. Yes, a large part of that is because of the overlooked talent possessed by their young stars, but most of it is because of the defensive system that Stevens has implemented. That, and Al Horford is their center.

That type of cohesion and communication on defense is what every team strives for. The juxtaposition in game one was stark. The Cavaliers appeared frantic, confused and reactionary on the defensive end. The Celtics; composed, seamless, effortless.

As I watched this massacre from Boston, my mind wandered to the Denver Nuggets, a team whose defensive deficiencies are well documented.

Jamal Murray was one of the league’s worst defensive point guards last season. That’s something that can be mitigated by length on the wing and rim protection, but Denver is severely lacking in both of those areas. Nikola Jokic is perhaps somewhat unfairly maligned for his ultimate defensive impact, but there’s a clear ceiling to his ability to help his team on that end.

Those two don’t just fail to mitigate each other’s weaknesses, it’s all compounded by them playing together. Even Gary Harris, the best defensive player of the core, lacks length on the perimeter. As long as Denver is riding with this core, it appears that they are living and dying by the offensive sword.

Last season, Jokic-ball produced the league’s most potent offense. Despite the injuries and the mind boggling Mason Plumlee-Nikola Jokic frontcourt experiment, the Nuggets still produced the sixth most points per 100 possessions this season, per cleaningtheglass.com. Denver has the offense to run with anyone. But is that enough?

An elite offense can get you into the playoffs, and it might even secure you a favorable seed. But you probably won’t go far without a strong defense. Not in this league. Not unless LeBron James is on your team.

So much of the conversation surrounding the Nuggets is regarding what it might take to get them into the playoffs, we haven’t really had the chance to discuss what it will take for them to succeed once they’re there. The Nuggets simply cannot trot out a bottom of the barrel defense and hope to compete with these teams.

A full season of Paul Millsap should help, but they’ll need some help on the wing. With such limited cap space, and a clear commitment to this young core, this front office has their work cut out for them on that front.