The history of several other commissioner elections shows that a deadlock among the known candidates can produce the unexpected — and can damage the chances of favorites.

In late 1968, there was no clear consensus among owners to replace William D. Eckert as baseball commissioner. At first, it was a battle along once-rigid hierarchical league lines between Michael Burke, the president of the Yankees, and Charles Feeney, a vice president of the San Francisco Giants. Burke could not drum up National League support; Feeney got some American League backing but not enough to win. Other names were proposed, including those of Lee MacPhail, the Yankees’ general manager, and John McHale, the president of the Montreal Expos, who had not yet played their first game.

After 19 ballots taken over 13 hours at a Chicago airport hotel, the owners took a breather until early February. Eckert, whom the owners had dismissed, stayed on.

The owners reconvened in Bal Harbour, Fla., but knew that neither Burke nor Feeney could get the 75 percent of the votes needed in each league to win. They needed someone new — and an insider with a distinctive name, Bowie Kuhn, was suggested. Kuhn was then a lawyer for the National League. The 24 owners elected him unanimously, initially for a one-year term. He would serve a tumultuous 15-year tenure that was characterized by his resistance to free agency, his battles with the union chief Marvin Miller and his suspension of the Yankees’ owner, George Steinbrenner, for illegal campaign contributions.

The last three N.F.L. commissioners were not elected quickly.

In 1960, owners could not name a commissioner after more than 20 ballots. Marshall Leahy, a San Francisco lawyer; Austin Gunsel, a former F.B.I agent who became the acting commissioner after the death of Bert Bell; and Don Kellett, the general manager of the Baltimore Colts, could not get enough votes. The Pittsburgh Steelers’ owner, Art Rooney, suggested seven other candidates, including Happy Chandler, the former baseball commissioner, and Don Miller, one of Notre Dame’s Four Horsemen. But nowhere on Rooney’s list was the man finally elected: Pete Rozelle, the general manager of the Los Angeles Rams.