Dana X. Bible, and Notre Dame coach Frank Leahy were advocates. Shaughnessy was an advisor to Halas in the 1930s while the head coach at the University of Chicago. The T became much more viable in 1933 when passing was legalized anywhere behind the line of scrimmage (previously, the passer had to be five yards behind the line). Halas recruited Solly Sherman, the quarterback for the University of Chicago because of his experience with the T-Formation under Clark Shaughnessy. Solly then taught Sid Luckman the system. Sherman, a former halfback, had torn his meniscus in college, and converted to quarterback his senior year when Shaughnessy installed the T-formation at the University of Chicago. Eventually he played backup to Sid Luckman with the Bears in 1939 and 1940 and retired so that he could join the war effort. Sid Luckman went on to win four NFL championships in the 1940s. Sid Luckman, in his book Luckman at Quarterback written in 1949, stated that several hundred plays in the Chicago Bears play book gave him over 1,000 options for man-in-motion deceptions, complicated blocking schemes and multiple passing options not previously available. The last team to run the single-wing in the NFL, the Pittsburgh Steelers, converted to the T in 1953. Since that time, the T, and all its variants, have dominated offensive football and created the American football now employed throughout the NCAA and NFL. The T is referenced in the Chicago Bears fight song, "Bear Down, Chicago Bears", written after the 1940 championship over Washington. "We'll never forget the way you thrilled the nation, with your T formation..." Additionally, two books detail the development of the T with the Bears. The Chicago Bears by Howard Roberts written in 1947, credits several coaches including Ralph Jones and Clark Shaughnessy for upgrading the T and teaching it to a succession of Bears QBs. The Wow Boys by James W. Johnson written in 2006 tells the story of the Stanford University football season of 1940. The arrival of Shaughnessy and his T offense led to a 10–0 season and a victory in the Rose Bowl over heavily favored University of Nebraska. The Bears' thumping of the Washington Redskins, 73–0, a few weeks earlier caused a sensation. The T swept college and pro football. The brain trust that created the T was always anchored by Coach Halas, who had the savvy for what worked and