The NBA has officially announced the participants in the 2019 AT&T All-Star Slam Dunk Contest.

The four participants will be Dennis Smith Jr. of the Knicks, Miles Bridges of the Hornets, John Collins of the Hawks, and Hamidou Diallo of the Thunder.

According to Oliver Maroney of Lineups.com, Derrick Jones Jr. of the Heat was originally set to appear in the contest. However, after suffering a knee injury on January 27, he was replaced by Diallo.

The only returning participant of the four is Smith. In 2018, he represented the Mavericks and  finished third behind runner-up Larry Nance Jr. and winner Donovan Mitchell.

The rules of the contest, as listed by Tim Cato of SB Nation, are as follows:

Four contestants, who each dunk twice in the first round

Two contestants with the highest combined scores from the first round will advance to the second round

The contestant with the highest combined score in the second round is the winner

Dunks are evaluated by five judges and can earn up to 50 points

Smith is averaging 12.8 points, 3.0 rebounds and 4.4 assists on the season. The 21-year-old has accumulated 21 dunks this season, all with Dallas prior to his trade to New York in this Kristaps Porzingis deal.

Bridges, 20, has averaged 6.6 points, 3.6 rebounds and 1.0 assists over 50 games with Charlotte this season. He has tallied 36 dunks on the year.

The 21-year-old Collins is averaging 19.6 points, 10.0 rebounds and 2.2 assists this season. The Hawks' power forward has slammed 103 dunks this season, ninth-most in the league.

The injury replacement Diallo has averaged 4.4 points, 2.2 rebounds and 0.4 assists. In his rookie season, the 2o-year-old has posted 22 dunks thus far.