Other basketball leagues in 1947:    
BAA  ·  NBL
By 1946, the American Basketball League was losing players and teams to both the NBL and BAA, and was no longer considered a major league. It folded entirely after the 1953 season.
First Round
Semi-Finals
ABL Champ.
0
TRE 2
JC 1
PHI 2
PHI 1
TRE 2
BKN 1
BAL 2
BAL 0
TRE 1
Champ
TRE
1946-47 ABL Champion Trenton Tigers
z: best record, c: conference winner, y: division winner, w: wildcard, x: clinched playoff spot
Trenton declared league champion when Baltimore refused to participate in finals.

1st Round

Best of 3-game series
DateAwayScoreHomeSeries
???Jersey City 48-56 Philadelphia PHI 1-0
???Philadelphia 60-63 Jersey City Tied 1-1
???Jersey City 50-56 Philadelphia PHI 2-1

1st Round

Best of 3-game series
DateAwayScoreHomeSeries
??? () 39-67 Trenton (ABL) TRE 1-0
??? () 52-54 Trenton (ABL) TRE 2-0

Semi-Finals

Best of 3-game series
DateAwayScoreHomeSeries
??? () Bkn. Gothams 80-66 Baltimore (ABL) BKN 1-0
??? () Bkn. Gothams 53-80 Baltimore (ABL) Tied 1-1
??? () Bkn. Gothams 46-70 Baltimore (ABL) BAL 2-1

Semi-Finals

Best of 3-game series
DateAwayScoreHomeSeries
??? () Philadelphia 64-81 Trenton (ABL) TRE 1-0
??? () Trenton 42-46 Philadelphia (ABL) Tied 1-1
??? () Trenton 48-46 Philadelphia (ABL) TRE 2-1

ABL Championship

Best of 3-game series
DateAwayScoreHomeSeries
??? () Baltimore ?-?
FF
Trenton (ABL) TRE 1-0