The two-time defending champs are in trouble. The upstart challengers from Canada have them on the ropes with a chance to land a historic haymaker on Monday night.

The Toronto Raptors have built a 3-1 series lead in the NBA Finals thanks in large part to their ability to control the Golden State Warriors' offensive production -- especially from the Dubs' role players, who have mostly been awful in this series. Even with Kevin Durant now planning to play, Golden State needs some help beyond its star backcourt to extend this series, no matter how ready KD is to contribute.

All of the Warriors' key metrics are disturbing, but as we approach Game 5 in Toronto on Monday (9 p.m. ET, ABC/ESPN App), let's start at the top with the most telling metric at the team level: net rating.

Net rating

Through the lens of net rating, this 2019 matchup currently stands as the third-most-lopsided Finals of the decade. It's also the worst Finals performance of the Splash Brothers era.

Warriors' net rating in Finals Year Opponent GSW NET RTG 2015 CLE 7.8 2016 CLE -0.5 2017 CLE 6.1 2018 CLE 16.6 2019 TOR -8.0

Offensive efficiency

This season, NBA teams on average scored 110.4 points per 100 possessions. In the Finals so far, the defending champs are managing a bleak 107.2 points per 100 -- a minuscule number for this dynasty.

The Raptors' players and coaches deserve a lot of credit for their defensive efforts against the Warriors. In last season's Finals, the Warriors had an outrageous offensive rating of 122.1, and in the 2017 Finals that number was 120.4.

But those lofty marks are light-years ahead of what the Warriors have accomplished through four games, during which they have struggled to score at even an average clip. The loss of Kevin Durant hurts, but the Warriors easily logged the best offensive efficiency in the conference finals without him, scoring 113.3 points per 100 possessions against the Portland Trail Blazers.

Effective field goal percentage

As Dean Oliver taught us, the most important component of offensive efficiency is effective field goal percentage, and a quick tour of the Dubs' eFG this series reveals big trouble in Splashtown. 2019 NBA Finals Find everything you need to know about Toronto's first NBA title. • Raptors in 6: News, reaction and more

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It should come as no surprise that the greatest shooting dynasty we've ever seen has led the NBA in the most important shooting metric for five consecutive seasons. This season was no exception, as the Warriors led the league with an eFG of 56.5%, well above the NBA average of 52.4%.

Shooting efficiency is one of the core elements of the Dubs' story, but in these Finals, their eFG is a lousy 50.3%. The Cavs ranked 29th in the NBA this season with the exact same eFG, and folks, any time your shooting numbers can be compared with that of the 2018-19 Cavs, you're probably not destined for the Larry O'Brien Trophy.

Durant's potential impact

You know what's likely to help the Warriors' shooting woes? The return of Durant, who is arguably the greatest individual scorer on the planet. Before he got hurt, Durant was leading all playoff scorers, putting up 34 points per game while posting 50/40/90 levels of efficiency. Durant had an average eFG of 58.0%. When he was on the court the Dubs' offensive rating was 117.4 and their overall eFG was 55.4.

Granted, those high numbers came in earlier rounds against less accomplished defenses, but still, the reintroduction of even a banged-up Durant should provide the Warriors with another dangerous weapon and restore some of their trademark offensive efficiency.

Durant isn't just the world's best midrange scorer, he also commands a ton of defensive attention. As the Raptors have to devote more of their defensive resources to him, it should make life easier for the Warriors' role players, who have almost all been very inefficient in this series so far.

Durant's reappearance should represent a rising tide for all of his teammates' shooting numbers, even if he isn't able to do much scoring on his own. KD acting as an overqualified catch-and-shoot specialist should still be enough to give the Warriors a much-needed scoring boost.

The role players

Golden State's poor team-level struggles are just a composite of multiple individual struggles, and when we drill down to the shooting efficiency of the team's most active shooters, it's easy to tell what's happening.

Remember, anything below a 50 eFG is generally regarded as poor.

Warriors' NBA Finals efficiency Player Finals FGA Finals eFG Stephen Curry 88 50.6 Klay Thompson 52 68.3 Draymond Green 41 43.9 Andre Iguodala 29 44.8 Quinn Cook 24 45.8 DeMarcus Cousins 23 32.6 Shaun Livingston 17 41.2 Alfonzo McKinnie 15 43.3 Jonas Jerebko 14 39.3 Kevon Looney 13 69.2

The problem is the Dubs' role players are almost all struggling to score at acceptable rates. Aside from Stephen Curry, Klay Thompson and Kevon Looney, every Warrior who has shot at least four times per game this series has an eFG below 46%, and the exact dudes who needed to step up in Durant's absence have flailed instead. From a scoring perspective, DeMarcus Cousins and Draymond Green have been especially disappointing.

When the Warriors added Cousins last summer, the NBA internet went bonkers as yet another All-Star was joining an already dominant team. On paper, with Durant sidelined, the 2019 Finals would be Boogie's opportunity to show the world he's a dominant superstar capable of playing winning basketball on the game's biggest stage. It hasn't worked out as he works his way back from a quadriceps tear. Cousins didn't even finish Game 4 because he has been atrocious on both ends of the court: too slow on help defense and too inefficient as a scorer.

With Cousins on the court this series, the Dubs have an offensive rating of just 97.9. That jumps to 110.2 when he sits. As an individual scorer he has been a mess, making just 5 of 12 shots in the restricted area and 2 of 11 shots outside of it. In the regular season, Cousins logged a respectable 51.5 eFG, but even in a low-usage scenario in this series he has been arguably the most inefficient scorer in either team's rotation. If his exclusion at the end of Game 4 is a fair indicator, Boogie's down production might cost him playing time in Game 5, and even more than that, at this summer's negotiating tables.

When you plot out the Warriors' Finals performances over the past five seasons, you can quickly see that this year's role players have been ineffective scorers relative to previous cohorts.

The Warriors have rarely had rotation guys put up bad scoring numbers, but in this year's Finals they have a bunch of them -- you can see them in pink in the lower left of that chart. Compare those low-efficiency numbers to the dark blue dots from last year, when none of the Warriors had an eFG below 50.

In their previous four Finals appearances, the Warriors had only five players who averaged more than four shots per game with an eFG below 46. This season's team has six: Cousins, Green, Jonas Jerebko, Shaun Livingston, Quinn Cook and Andre Iguodala. Editor's Picks Lowe: What Kawhi and the Raptors have done to the Warriors

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That not-so-fantastic six has combined to shoot 57-of-148 (38.5%), with a dismal composite eFG of 41.9 while accounting for nearly 45% of the Warriors' shots. Their collective stank is not just pulling down the overall shooting numbers of a team led by superstars who will be remembered for their incredible shooting stats, it's also destroying any chance they have of beating a team that has been much better on both ends of the court.

On his way out of town in 2016, Harrison Barnes was disparaged because of his poor play in the Finals. Well, as you can see, there's a cluster of players this year who are emulating Barnes' poor Finals showing.

But even as the Warriors' role players have been woeful as shooters, the Raptors' supporting cast has been solid. So far this series, 16 total players are averaging at least four field goal attempts per game. Of that group, seven of the eight lowest eFGs belong to Golden State.

When you compare the shooting numbers of both squads, you can quickly see that Toronto's role players have been a lot more efficient.

From a scoring perspective, Curry, Thompson and Looney have been good. Everyone else on the Dubs has been bad. While Golden State is trying to absorb the lackluster shooting performances of its role players, the Raptors' non-stars have been propelling much of their success. Serge Ibaka was great in Game 4. Danny Green was great in Game 3. Marc Gasol was great in Game 1. The Warriors don't really have any such performances from their role players.

As the series shifts back to Toronto for a massive Game 5, we'll all have our eyes on Kawhi Leonard, the Splash Brothers and Durant. But if the first four games of this series have taught us anything, it's to keep an eye on the role players too. Their performances are vital.