The Knicks have played an additional 50 games since their opening night disaster in Boston, largely achieving their stated goal of steadily improving over the course of a season they began with two new starting players.

More than three months later, the Knicks (34-17) finally will face the defending NBA champions for a second time — and with a significant chance to pull even in the loss column Saturday night at the Garden.

It also will mark the first game for the third-seeded Knicks and the No. 2 Celtics (36-16) after both teams essentially stood pat ahead of Thursday’s trade ᴅᴇᴀᴅline.

“It’s the next test,” Tom Thibodeau said after practice Friday in Tarrytown. “It’s about understanding how you prepare for each game and what are the strengths and weaknesses of the team. We have to know them well.