Golf's biggest tournament began today, but without golf's leading man. Tiger Woods withdrew from The Masters this year after having back surgery, leaving the event without its marquee attraction. Plenty of folks will still tune in, but how much will his absence impact the TV ratings?

This is the first time that Woods has missed the Masters since his first amateur appearance in 1995. Without him, The Chicago Tribune estimates that the broadcast could lose 20 percent of its viewers from last year. The former president of CBS Sports Neal Pilson goes further, telling CNBC that Woods typically contributes about a 30-35 percent ratings increase. When Woods missed part of the 2009 season with an injury, Nielsen found that ratings for Woods-less tournaments were half the size as usual. But that number was for smaller tournaments, and not the Masters, which has its own mystique for even casual fans.

Since the last Woods-less Masters was 20 years ago, and the TV and golfing landscape has changed dramatically since then, it wouldn't be fair to compare the ratings from this week to the early 1990s. But we can see his impact on the tournament by looking at the years in which Woods was not competitive. Tiger has won the Masters four times, but he has also finished far behind the leaders on a number of occasions. In 2012, for example, Woods suffered through his worst Augusta performance as a pro, and ratings noticeably suffered. If he doesn't have a shot at another green jacket, a lot of people aren't interested.

To get a sense of what you might expect, we looked at the average Masters' viewership over the Saturday-Sunday broadcasts throughout his career and compared them Tiger's place on the leaderboard. 

First, here are the ratings when Woods was a non-factor in the final rounds. We defined "non-factor" as Woods being at least five shots away from the lead entering Sunday's round. That has happened six times since 1996, when he missed the weekend cut as a still-amateur golfer. 

And here is a chart, equally scaled, of the ratings when Woods is either in the lead entering the last day or within five strokes.

As these charts show, the three most-watched Masters in this timeframe all involved a competitive Woods on the final day: 1997, 2001, and 2010. In addition, six of the eight most-watched Masters since 1996 involved Woods in the hunt through the final day.

Taking these all together, here's the average when Woods was competitive vs. his non-competitive starts.

When Woods was in the lead or within the lead entering the final day, the Masters ratings averaged 1.2 million more people than when he was more than five shots out of first place. That 1.2 million means that a Masters without a competitive Woods provides, on average, a 10 percent drop in ratings. That drop is significantly lower than the guesses from The Chicago Tribune and CBS Sports former president, suggesting they might be overstating the matter. But his power as a draw is very real.

Obviously, there are other factors that can affect the ratings, like holiday weekends; the popularity of the other leaders; the competitiveness of the final holes; the chances for a playoff, etc. But even an exciting finish doesn't compare to the effect that Tiger has on the general public. For example, the highest-rated tourney on this list, 1997, was the least competitive Masters of all time. Woods smashed the field, winning by 12 strokes, a record that still stands. The lowest? 2003, when Len Mattiace came from five strokes back on the final day to force a playoff. But the winner was little-known Canadian Mike Weir. Woods collapsed and finished 15th.

In any case, The Big Lead notes that ratings will be buoyed by the Masters not being on Easter Sunday. So CBS has that to look forward to, at least.