The phrase "to reach the playoffs" means to qualify or make it into a tournament or series of games that determines the champion of a sport. Full definition
In 2014, five of the league's six teams reached the playoffs. (sportstarsmag.com)
We should note that we eliminated the juice in order to calculate the implied probability for each team reaching the playoffs. (sportsinsights.com)
He helped the Pistons reach the playoffs for the first time in seven years and averaged 16 points, a league - leading 15 rebounds, and over a block per game. (sbnation.com)