Schedule and 2017-18 Results
Regular Season Records: Boston 55-27, Cleveland 50-32
Game 1 on Sunday, 13 May: Cleveland loses at Boston, 108-pts-83
Game 2 on Tuesday, 15 May: Cleveland loses at Boston, 107-pts-94
Game 3 on Saturday, 19 May: Boston loses at Cleveland, 116-pts-86
Game 4 on Monday, 21 May: Boston loses at Cleveland, 111-pts-102
Game 5 on Wednesday, 23 May: Cleveland loses at Boston, 96-pts-83
Game 6 on Friday, 25 May: Boston loses at Cleveland, 109-pts-99
Game 7 on Sunday, 27 May: Cleveland wins at Boston, 87-pts-79

SERIES NOTES:

After Game 7: The Cleveland Cavaliers visited and defeated the Boston Celtics 87-pts-79 to complete a 4-games-3 best-of-7 MLB/NBA/NHL playoff series 1380 victory. With the series 1380 win, the Cleveland Cavaliers improve their best-of-7 NBA playoff series record to 23-10 overall and 5-3 (with an active four-Semifinals winning streak) in the Semifinals round. With the series 1380 loss, the Boston Celtics see their best-of-7 NBA playoff series record fall to 66-27 overall and 20-11 in the Semifinals round. The win order for the victorious Cleveland Cavaliers in series 1380 was LLWWLWW: Series 1380 thus becomes the second NBA Semifinals-round series, the fifth NBA series (all rounds), and the 15th MLB/NBA/NHL series (all rounds) to follow that win order to completion. The visiting Cleveland Cavaliers trailed the Boston Celtics by eight points after the first quarter of series 1380 Game 7, but prevailed. In the history of best-of-7 NBA playoff games since 1947, inclusive, road teams down eight points after the first quarter had a game record of only 15-80 (.158).

After Game 6: The Cleveland Cavaliers hosted and defeated the Boston Celtics 109-pts-99 to tie best-of-7 MLB/NBA/NHL playoff series 1380 at 3-games-all. When tied 3-games-all in a best-of-7 MLB/NBA/NHL playoff series, the Boston Celtics have a Game 7 record of 23-8, while the Cleveland Cavaliers have a Game 7 record of 4-2. The Boston Celtics have a 20-4 Game 7 record in Boston. The Cleveland Cavaliers have a 1-2 Game 7 record on the road (with the sole victory occurring at Golden State over the Warriors in the 2016 NBA Finals). The 31 Game 7 appearances irrespective of site, the 23 Game 7 wins irrespective of site, the 24 Game 7 home appearances, and the 20 Game 7 home victories by the Boston Celtics all top their respective categories in best-of-7 MLB/NBA/NHL playoff Game 7 history. Irrespective of win order or of round, home teams in best-of-7 NBA playoff Game 7s have a 104-26 (.800) record.

After Game 5: The Boston Celtics hosted and defeated the Cleveland Cavaliers 96-pts-83 to take a best-of-7 MLB/NBA/NHL playoff series 1380 lead of 3-games-2. When leading a best-of-7 MLB/NBA/NHL playoff series 3-games-2, the Boston Celtics have a series record of 39-3 and a Game 6 record of 21-21. When trailing a best-of-7 MLB/NBA/NHL playoff series 3-games-2, the Cleveland Cavaliers have a series record of 1-6 and a Game 6 record of 2-5. The sole Cleveland victory in the wake of a 3-games-2 best-of-7 NBA playoff series deficit occurred in their last such series, in series 1316 against the Golden State Warriors (in the 2016 NBA Finals). The sole best-of-7 NBA Semifinals series in which the team leading WWLLW @ HHVVH (i.e., Boston in series 1380) did not win the series was series 243, in which the old Baltimore Bullets (II) defeated the New York Knickerbockers in Games 6 and 7 of their 1971 NBA Semifinals series.

After Game 4: The Cleveland Cavaliers hosted and bested the Boston Celtics 111-pts-102 to tie best-of-7 MLB/NBA/NHL playoff series 1380 at 2-games-all. When tied 2-games-all in a best-of-7 MLB/NBA/NHL playoff series, the Boston Celtics have a series record of 32-12 and a Game 5 record of 32-12, while the Cleveland Cavaliers have a series record of 7-6 and a Game 5 record of 8-5.

After Game 3: The Cleveland Cavaliers hosted and defeated the Boston Celtics 116-pts-86 to reduce the Boston Celtics best-of-7 MLB/NBA/NHL series 1380 lead to 2-games-1. When leading a best-of-7 MLB/NBA/NHL playoff series 2-games-1, the Boston Celtics have a series record of 42-3 (with an active ten-series winning streak) and a Game 4 record of 18-27. When trailing a best-of-7 MLB/NBA/NHL playoff series 2-games-1, the Cleveland Cavaliers have a series record of 5-5 and a Game 4 record of 8-2. In best-of-7 NBA playoff series history, teams losing Games 1-2 on the road and winning Game 3 at home by 30+ points (such as the Cleveland Cavaliers in series 1380) have a 2-3 series record, with the two wins characterized by a Game 4 loss and then wins in Games 5-7, and with the Cleveland Cavaliers having notched the last such series victory (in series 1316, over the Golden State Warriors in the 2016 NBA Finals).

After Game 2: The Boston Celtics hosted and topped the Cleveland Cavaliers 107-pts-94 to take a best-of-7 MLB/NBA/NHL playoff series 1380 lead of 2-games-nil. When leading a best-of-7 MLB/NBA/NHL playoff series 2-games-nil, the Boston Celtics have a series record of 37-0 and a Game 3 record of 14-23. When trailing a best-of-7 MLB/NBA/NHL playoff series 2-games-nil, the Cleveland Cavaliers have a series record of 2-6 and a Game 3 record of 5-3.

After Game 1: The Boston Celtics hosted and bested the Cleveland Cavaliers 108-pts-83 to take a best-of-7 MLB/NBA/NHL playoff series 1380 lead of 1-game-nil. When leading a best-of-7 MLB/NBA/NHL playoff series 1-game-nil, the Boston Celtics have a series record of 55-5 (with an active 11-series winning streak) and a Game 2 record of 37-23. When trailing a best-of-7 MLB/NBA/NHL playoff series 1-game-nil, the Cleveland Cavaliers have a series record of 5-9 and a Game 2 record of 6-8. The 26-point halftime lead by the Boston Celtics over the visiting Cleveland Cavaliers in series 1380 Game 1 was the largest halftime lead in Game 1 of a best-of-7 NBA Semifinals series since series 768, in which the Utah Jazz hosted and led the Los Angeles Lakers 61-pts-35 in Game 1 of their 1998 NBA Semifinals series. While the Boston Celtics own an 18-2 Semifinals series record (with an active six-series winning streak) upon leading a best-of-7 NBA Semifinals series 1-game-nil, the two series losses (series 273, in the 1973 NBA Semifinals to the New York Knickerbockers; series 408, in the 1982 NBA Semifinals to the Philadelphia 76ers; both in seven games) both occurred after Game 1 home-court blowout victories (134-pts-108 vs New York; 121-pts-81 vs Philadelphia).

Pre-series assessment: In the 2017-18 NBA regular season, the Boston Celtics finished five games ahead of the Cleveland Cavaliers. From 1947 through the 2018 NBA and NHL Quarterfinals rounds, when NBA teams led their best-of-7 playoff series opponents by five regular-season games, they have posted a best-of-7 playoff series record of 25-9 (.735) in those series against those opponents. MLB/NBA/NHL best-of-7 playoff series 1380 is the 93rd best-of-7 NBA playoff series for the Boston Celtics, and the 33rd for the Cleveland Cavaliers. In best-of-7 NBA playoff series, the Boston Celtics have an all-rounds series record of 66-26, a Semifinals-round series record of 20-10, and a Game 1 record of 60-32, while the Cleveland Cavaliers have an all-rounds series record of 22-10, a Semifinals-round series record of 4-3, and a Game 1 record of 18-14. Series 1380 is the seventh best-of-7 NBA playoff series meeting between the Boston Celtics and the Cleveland Cavaliers. The teams have split their previous six best-of-7 NBA playoff series meetings, with Cleveland winning the last two (series 1347, in the 2017 NBA Semifinals; series 1270, in the 2015 NBA Preliminary round).