(Reuters) - The old adage that a playoff series does not begin until a home team loses does not apply to the Cavaliers, who know a defeat in Game Three could all but finish their NBA Finals chances against the Golden State Warriors.

With LeBron James and the Cavs trailing 2-0, the best-of-seven championship series shifts to Cleveland on Wednesday.

After two emphatic home successes, the all-conquering Warriors would seize a 3-0 lead with a road victory that would extend their win streak against the Cavs to eight including the last three games of their NBA Finals triumph last season.

No National Basketball Association team has ever come back from 3-0 down to win the championship.

However, Cavaliers coach Tyronn Lue remained optimistic.

“The guys are not discouraged,” Lue said after Sunday's crushing 110-77 defeat in Game Two at the Oracle Center.

"They did what they were supposed to do, they won two games at home. We’ve got to get home and do the same.”

Logical enough, but against Golden State, the NBA's best ever regular season team with 73 wins, it is a tall order.

James acknowledged as much.

"We've got to be better at all facets of the game, both offensively and defensively, both physically and mentally," the four-time league MVP told reporters.

The Cavaliers' leader, appearing in his sixth NBA Finals in a row, placed a lot of the blame on himself.

"I turned the ball over way too much," said James, who committed eight turnovers. "I've got to be better. I've got to be better with the ball.

"I can't be careless with the ball, especially in the paint where a lot of reaching and things of that nature happen."

The Warriors, noted for the explosive long-range shooting of 'Splash Brothers' guards Stephen Curry and Klay Thompson, have played a swarming, opportunistic defense anchored by the shot-blocking down low by big Australian center Andrew Bogut.

Golden State has shown impressive versatility, relying on their bench to do the lion's share in Game One, while leaning on rugged Draymond Green to lead the scoring parade with 28 points in the Game Two rout.

"The way they're playing defense against our guards, Draymond's going to be open all day," said Warriors coach Steve Kerr.

Kerr added that he was attuned to his bench players, having been a reserve for much of his NBA playing career.

"I have a lot of empathy for bench players having been one myself," Kerr said. "It's a hard job to stay ready and sometimes not play. We have a group of real pros on the bench."

"(Brazilian Leander) Barbosa, (Shaun) Livingston - obviously Andre (Iguadola) is one of the best players in the league when we bring him off the bench."

The Golden State coach knows an early series lead is no guarantee of success as his Warriors trailed the Oklahoma City Thunder 3-1 before roaring back to win the Western Conference finals.

"I think the Oklahoma City series definitely made us stronger," Kerr said. "It wasn't a whole lot of fun, and we barely escaped.

"It's 2-0, so we did our job. We won our two home games. There is obviously a long way to go, so we're not celebrating."

(Reporting by Larry Fine; Editing by Ken Ferris)