Every game is critical in this series, but game one has an especially interesting dynamic. The Miami Heat have never trailed in a series. They've never faced any adversity in the playoffs. They've folded in the regular season at times when the going got tough, and while they since rebounded, they haven't had a real challenge since then.
If Chicago wins game one, they put pressure on Miami that they haven't felt in a long time. On the other hand, Chicago has already fought back from an 0-1 deficit. They've responded to such pressure in the past. It would be much more difficult against Miami than Atlanta, but the Bulls have showed tremendous mental toughness all season long.
Energy, focus, and more energy
The Bulls have not played well coming off of layoffs. For that reasons, it's probably advantageous that the series went six games against Atlanta and shortened their layoff some. It's impossible to believe that the Bulls are taking the Heat lightly. They're confident, but they know what a challenge this is.
As for the Heat, they celebrated like they won the championship after beating the Celtics. They noted prior to round two starting that they feared Boston more than Chicago. I don't know that they're taking Chicago lightly per se, but I believe they were sincere in their belief that Boston was the tougher team.
Hit the glass or stop the transition game?
The harder Chicago attempts to hit the offensive glass the greater the chance of Miami getting out in transition. This is going to be one of those seesaw wars. If Miami attempts to leak out too much they might give up too many offensive rebounds as well.
Which team can really impose what they want to do here? Does Chicago hit the glass enough that Miami slows down their transition game or does Miami get enough points in transition to force the Bulls to get back on defense more?
How this battle goes will likely go a long way in determining the outcome of the series.
Chicago played defense at an extraordinary level against Atlanta. They swarmed so fast and hard that the Hawks could simply do nothing. The Bulls rotated so smoothly and quickly that even when Atlanta passed out of the double team they couldn't hit the open man fast enough to get off a shot.
The Bulls need to hit the Heat with the same type of defense. They need to swarm Wade and LeBron but still rotate quickly enough to stop open threes and easy baskets by other players. To the extent the Bulls can do that will control whether Miami's offense off or not.
It's only one game, but it feels like so much more. Chicago doesn't lose consecutive games frequently and hasn't lost three in a row all season. Getting an early lead in the series on Miami will put incredible pressure on them, and they haven't necessarily responded that well to pressure this season.