Isaiah Thomas knows how special it is for Boston to wrap up its season as a No. 1 seed, but he is concentrating on the Celtics' first-round matchup against the Bulls. (1:31)

What's at stake on the final day of the NBA's regular season? How about the No. 1 seed in the Eastern Conference, with the Cavaliers and Celtics separated by a single game with one game left?

With the playoff picture changing daily, here's an updated look at the postseason races to watch, with the latest Basketball Power Index (BPI) projections of where teams are likely to finish.

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Editor's note: BPI odds through April 11 games.

Race for No. 1: Cavs vs. Celtics

TEAM RECORD GB HOME/ROAD 1. BOS 53-29 -- 0/0 2. CLE 51-31 2 0/0 Cleveland owns

head-to-head tiebreaker

Boston Celtics

Next game: Season complete

Cleveland Cavaliers

Next game: Season complete

Losers of four straight games, Cleveland will enter the playoffs as the No. 2 seed in the East after resting its stars in the regular-season finale against the Raptors. Boston, meanwhile, took care of the Bucks to leave no doubt and finish first in the East.

Wild, wild East: Race at the bottom

TEAM RECORD GB HOME/ROAD 7. IND 42-40 -- 0/0 8. CHI 41-41 1 0/0 8. MIA 41-41 1 0/0

Indiana and Chicago are the last two teams to qualify for the East playoffs. Both teams won their Wednesday finale, as did Miami, but the Heat were left out by virtue of losing the head-to-head tiebreaker with Chicago. The Heat got to .500 after being 19 games under .500; that is the most games under .500 in NBA history by a team that managed to get back to .500.

All of the Western Conference matchups are set for the first round of the NBA playoffs, with the last question to be determined being home-court advantage between the Clippers and Jazz.

Race for No. 4: Clippers vs. Jazz

TEAM RECORD GB HOME/ROAD 4. LAC 51-31 -- 0/0 4. UTAH 51-31 -- 0/0 L.A. Clippers own

head-to-head tiebreaker

LA Clippers

Next game: Season complete

Utah Jazz

Next game: Season complete

The Clippers and Jazz both won their season finales on Wednesday, leaving the Clippers at No. 4 and the Jazz at No. 5.

How important would home-court advantage have been to the Jazz? As the No. 4 seed, Utah would hold a 51 percent edge in a series with the Clips, according to BPI. But if the Jazz fall to the No. 5 seed, they would indeed be underdogs, with only a 41 percent chance to advance to the second round for a potential matchup with the Warriors.

More: Standings | Matchups | Playoff odds | Lottery odds