The Cavaliers had a full complement of NBA players once. There were three stars at the team's core instead of just one—a dynamic lead guard who could spell LeBron James from his creative duties and a floor-spacing forward capable of facilitating explosive offense. Even after losing Anderson Varejao (the team's starting center for the first quarter of the season), Cleveland had grown and remade itself into something playoff viable. So viable, in fact, that Kevin Love and Kyrie Irving's season-ending injuries couldn't budge the Cavs from their course to the NBA Finals.
It was there, and not until mid-series, that Cleveland's lack of depth became a potentially fatal issue. It has been charitably noted that the Cavs have run a seven-man rotation in these Finals. Among those seven are Matthew Dellavedova, whose spot success in defending Stephen Curry has since been rendered moot by fatigue and adjustment; Iman Shumpert, whose key contributions on offense have been missed layups and hesitant jumpers; J.R. Smith, for better and mostly worse; and James Jones, who moves laterally as if he were on tank treads. If not for James and the alternating success of Tristan Thompson and Timofey Mozgov, the Cavs would not have lasted long in this series.
Game 5, however, turned the series in such a way as to irritate the Cavaliers' rotational deficits. The Warriors again committed to running smaller lineups—this time by nipping usual starting center Andrew Bogut from the rotation and assigning his typical backup, Festus Ezeli, just three minutes of playing time. Where their game plan changed was in the treatment of Mozgov, who had powered his way to 28 points on just 16 shots the game prior. Cleveland followed up by posting Mozgov on the first possession of Game 5 and saw a full double team in response:
Even on that first attempt to post Mozgov, the problems in doing so were clear. Andre Iguodala had rotated down perfectly to cover for the doubling Harrison Barnes while Curry and Klay Thompson zoned up the top of the floor. To get any kind of momentum out of the double team, Mozgov would have to trigger a pass well beyond his demonstrated skill set. The fifth-year center doesn't have much experience in working his way out of double-coverage, much less the natural feel for playmaking that would allow him to exploit this kind of defense more creatively.
Here's what happened when Mozgov tried to set up the open man in scoring position after feeling the double:
Worse yet, the Warriors' defense seemed to finally strike the ideal balance in zoning up the middle of the floor as to take away the offense of Mozgov and Thompson despite undersize defense of both players. This kind of spacing just isn't tenable:
And so Cavs coach David Blatt pulled Mozgov from the game early and reinserted him only when Thompson needed a moment's rest. He played nine minutes in total. The Warriors can afford to do this; there are enough useful, usable players on Golden State's bench as to make dropping Bogut from the rotation a workable strategy. Cleveland, however, can't do the equivalent without running headlong into the same limitations that have been a problem throughout the series. Shorting Mozgov's minutes forces some other player to sop them up.
They were ultimately dispersed among wing players as the Cavs matched small for small. Kendrick Perkins and Brendan Haywood would be of no use against an opponent like the Warriors. Instead, Cleveland relied on Thompson at center as much as possible and force-fed playing time to Smith, Shumpert, Jones, and surprise entrant Mike Miller.
Jones and Miller logged a combined 32 minutes. They worked hard, played to their strengths, and made smart plays. They were also in way over their heads in contributing real rotation minutes to a desperate team. If Blatt had any alternative, he likely would have taken it. But of those veterans on Cleveland's bench, Jones and Miller are easily the most applicable to this particular matchup.
Smith actually began the game with his best half of the series: A 14-point flare up in which the career gunner hit four three-pointers. He would go scoreless in the second half as the Warriors played their close-outs even more attentively and switched on those occasions when Smith was given a pin-down screen like so:
On a deeper team, the quelled Smith might be replaced by a more capable all-around contributor. For the handicapped Cavs, he played 19 of a possible 24 minutes in the second half. There is no way forward but to rely on Smith.
This is why the Cavs' predicament is much more severe than mere exhaustion. Their rotation is short and the workload of the starters significant. The same is true for the Warriors, who played Curry, Iguodala, and Thompson for 40+ minutes in Game 5. What separates the rotations of those two teams is the power of choice. Warriors coach Steve Kerr has at least some freedom to mold his lineups to circumstance while still maintaining his team's strengths and identity. Blatt has only extreme options—like benching Mozgov—when he wants to trigger a change.
So Smith outstays his usefulness, Dellavedova (whose decision-making can be as spotty as Smith's at times) works to exhaustion, and James maxes out his production and playing time. The Cavs have found their bounds in the woe of a contracted roster. Now, facing elimination without the structural means to improve, they find their brink.