It wasn’t the record crowd that some, including the head of the Commission on Presidential Debates, had been predicting. But it was still a healthy turnout.

Fifty-seven million people tuned in to watch Friday’s first presidential debate between Democratic candidate Barack Obama and Republican candidate John McCain, according to early Nielsen estimates.

That was well below the biggest debate tally ever, 80 million, for the 1980 square-off between Ronald Reagan and Jimmy Carter. In fact, it didn’t make the top 10 most-watched debates in history, despite speculation beforehand that it could break records.

Frank J. Fahrenkopf Jr., co-chair of the CPD, had said as late as Friday night that the 80 million mark was in reach because of the huge interest in this year’s election.

Convention acceptance speeches by Obama and McCain roughly a month ago broke all sorts of records, and there’s been a huge bump in ratings for the cable news networks for their coverage of the election.

Viewership for this year’s debate, which included coverage on the Big Four broadcast networks, the three cable news networks, the Spanish-language broadcasters and PBS, could adjust significantly when final ratings are released.

The initial numbers are based on metered-market ratings across 55 DMAs, but that did not include estimates for Houston, where numbers have been delayed until today due to continuing issues stemming from Hurricane Ike.

The biggest tune-in percentage-wise came in St. Louis, where 82 percent of those watching television tuned in.

ABC led the Big Four networks with an average 9.8 million total viewers from 9 to 11 p.m., but those numbers do not account for time zone variances. Final numbers will be out later today.

Obama-McCain I drew about 5.5 million fewer viewers than the initial debate between President Bush and John Kerry four years ago. That debate was the most watched since the third debate of 1992 between Bill Clinton, George Bush and Ross Perot attracted 66.9 million total viewers.

That debate also was held on a Thursday night, one of the biggest of the week for television. Friday’s debate aired on one of the least-watched nights of the week, and could see an uptick when DVR numbers are added later.

There are two debates remaining for Obama and McCain, the next coming Oct. 7. There’s also a vice presidential debate this Thursday.