The Ivy League's most important game of the year takes place this Friday evening when defending champion Columbia faces Princeton. Both teams have swept their first six league contests, and the winner of Friday's contest will have the inside shot for the title.

Powered by All-American forward Jim McMillian, and All-Ivy guard Heyward Dotson, Columbia has rolled to a 15-1 season mark. The Lion's only loss so far has been to nationally third-ranked Santa Clara, 64-58.

McMillian, currently tied for second in League scoring with a 19.5 points per game average, also excells on defense. In the Lion's most recent outing, against Yale, he held Eli captain Thatcher Shellby scoreless as Columbia went on to a 69-48 romp. McMillian is also the Lion's top rebounder, clearing the boards 137 times in their first 14 games.

Dotson, ranking among the country's top field goal artists with a 60.6 percentage, gives Columbia tremendous attack potential and is versatile enough to shift to the center position when the Lions need help there.

But Princeton has gunners of its own in the League's top scorer, All-Ivy Jeff Petrie (22.2 points per game), and forward John Hummer, tenth in Ivy scoring with a 15.5 points per game output. And two-time All-Ivy center Chris Thomforde, 6-9, provides the muscle under the boards that the Tigers need to set up Petrie and Hummer.

In spite of its less outstanding over-all record (11-6) Princeton remains a formidable barrier to Columbia's hopes for their second consecutive title, and home court advantage will be a factor in the game.

Last year the Lions and Princeton split their home-and-home series, with Columbia winning 69-60 in New York, and the Tigers triumphing 68-47 at Princeton. Columbia has dropped its last two contests and 11 of its last 12 games at Nassau.

In other Ivy action, a Harvard man finally broke in among the top ten scorers in the League as All-Ivy forward Chris Gallagher took over the number nine spot with a 15.8 points per game average.

This week third-place Pennsylvania (4-2) meets Cornell Friday and Columbia Saturday, and Cornell and Yale, tied for fourth (3-3) will try to better their records with games against Penn and Harvard Friday, then Princeton and Dartmouth the next night. Brown is at Dartmouth and Harvard this weekend.