The varsity will be a 13-point underdog this Saturday when it faces a Yale squad which Crimson scouts rate as the Ivy League's top team today.

But observers who have compared the performance of the two teams against Penn say an upset would not be too surprising. And Yale's victory over Princeton Saturday was the result of an Eli refinement of the passing attack which the Crimson had used against the same opponent.

While the outlook is far from hopeless for the varsity, the improvement shown by Yale during the season has brought it near the position of relative dominance that its championship predecessors held last year. The team the Crimson faces Saturday is far different from the Yale squad which lost to Brown in early October. The Elis had only five returning starters, and weren't expected to compare to last year's Ivy League title holders.

Yale coach Jordan Olivar lacked experienced halfbacks and tackles, and had only one veteran for the quarterback slot. That one--Dick Winterbauer--has proved sufficient, however. Saturday, he moved into the total-offense lead in the League on the strength of 206 yards gained on 31 plays. He threw 14 completed passes, two of which went for touchdowns.

Eli passing was the main factor in the upset of Princeton, but Yale's use of a man in motion, along with a trailer back, baffled the Tigers and gave the Bulldogs an added boost. Yale alternated between the slot-T and the straight-T formations for the first time Saturday, following the pattern the Crimson had employed against the Tigers with some success.

John Pendexter, the Eli right end, is a doubtful starter in Saturday's game, but Mike Cavallon, who caught three touchdown passes against the Tigers, is ready to go in his place if necessary.

Gene Coker, a standout performer against Princeton, will start at fullback, and Winterbauer will be in his usual quarterback slot. The starting halfbacks will be Dick Winkler and Herb Hallas, who caught a 53-yard pass from Winterbauer in Saturday's game, only to have it called back on a penalty.

Rally, Fireworks Tonight

The traditional fireworks display and rally which mark the close of the last football practice will take place this evening at 6:15 at the Dillon Field House. Cheerleaders, the University Band, and undergraduates will try to provide the impetus for a victory over Yale.