While LeBron James is the "key" to any series that he participates in, the match-up between the Atlanta Hawks and Cleveland Cavaliers could arguably be determined by an individual battle that has little to do with the best player on the planet.
That face-off will take place between Kyrie Irving and Jeff Teague.
Interestingly, both point guards enter this series with legitimate injury concerns, though Irving's ailment appears to be more pressing. Cleveland's lead guard was severely limited by knee and foot issues during the team's series against the Chicago Bulls, but in advance of Game 1, Irving indicated that he would "definitely" play, despite a previous listing of "day-to-day".
Teague's injury battle has been documented in less meticulous fashion in recent days, but the All-Star has been visibly hampered by a sprained ankle in recent weeks. While he has repeatedly declined to cite the injury as a legitimate issue, Teague's explosiveness has been dampened by the ankle, and a four-day break between series could do wonders for his physical ability.
Beyond the injuries, the Irving-Teague battle is far-reaching. Kyrie Irving is one of the best offensive guards in the NBA, and the 23-year-old averaged more than 21 points per game in the regular season while shooting 41.5% from beyond the 3-point arc. When healthy, Irving is capable of breaking down virtually any defender off the dribble to create for himself or others, and even if he's hampered, the former number one pick is an elite shooter at the position when playing "second fiddle" to LeBron James when the point forward is creating.
Teague carries a different load for the Hawks, as the team famously integrates each of its five players offensively in a unique fashion. Still, the 26-year-old point guard is Atlanta's best bet for penetration and creation among the starting five, and it has been proven on a regular basis that the Hawks are simply different (read: better) offensively when Teague is threatening the defense by prodding and forcing movement by the opposition.
The other end of the floor is perhaps the most interesting for both players, and that is where their support systems come into play.
Neither Teague nor Irving is generally capable of taking the other player out of the game with strong defense, though it must be noted that Teague is the superior defender by a considerable margin. Normally, the Hawks may try to cross-match against a player like Irving, utilizing DeMarre Carroll (or even Kent Bazemore) as something of a "stopper" while hiding Teague off the ball, but with LeBron James on the floor, that is very difficult to do, leaving Teague on an island against Irving when both players are on the floor.
For Cleveland, it will undoubtedly be interesting to see how they handle the defensive match-ups. Kyle Korver is likely to be the "focal point" of the perimeter defense for the Cavs, with Iman Shumpert as a reasonable candidate to chase him all over the floor. However, Shumpert is a much better defender on the ball than off the ball, and against Korver, it takes a unique skill set to fight through the endless parade of screens and flares engineered to get the sharp-shooter in the best position to succeed.
The individual match-up between Korver and Shumpert takes on a mind of its own actually. As with anything in the NBA, straight-up position battles are nearly extinct, but it is reasonable to think that the pairing will guard each other on both ends. Korver's 35% shooting clip from beyond the arc (29% against Washington) in the playoffs has been out of character, but he was given the intense task of chasing Bradley Beal for the better part of six games, and with four days to get his legs back (and for Korver, a chance to retool his shooting stroke), it would be wise for Cleveland to keep their guard up against the best standstill shooter in the universe.
Defensively, Korver is certainly capable of slowing the likes of Shumpert and/or JR Smith. It would be a surprise to see Budenholzer deploy Korver against LeBron James for any length of time, and as a result, he will be affixed to whichever shooting guard is on the floor, with the ability to use his considerable traits as a responsible and effective help defender with length.
For me, the backcourt battle is a classic case of "closer than the experts think". Kyrie Irving is a star in the NBA, but while Jeff Teague hasn't received that level of recognition (and rightly so), he is exceedingly capable of playing Irving to a "draw", especially if Cleveland's point guard is hampered by injury. That is, essentially, Teague's charge in this series, keeping things close with Irving while the rest of the starters (sans a match-up against LeBron) win their individual battles through team basketball.
Jeff Teague must emerge, Kyle Korver must make shots at a Kyle Korver-like clip, and on the defensive end, limiting opportunities for non-LeBron members of the Cavs should be the focus. The Hawks don't need to "win" the backcourt battle to win the series, but they can't afford to lose it, either.