Wednesday: It's been 48 hours since the Westgate moved their line to Patriots -4, and the line is holding steady there.

Why is that significant? It appears professional bettors who might be looking to play the Patriots are staying patient in the hopes that the line could sink even further. If 4 was the magic number for those bettors, we would've likely seen the line quickly hop back to Patriots -4.5. That didn't happen.

Per Sports Insights, the online book 5Dimes is also dealing Patriots -4, while other listed books are sticking at 4.5 with varying amounts of juice. As of about 3 p.m. ET on Wednesday, 59 percent of the spread bets tracked by Sports Insights were on the Eagles, with the Eagles also making up 68 percent of the moneyline bets.

Monday: The story of the first week of Super Bowl betting was the continuous move of the line toward the Eagles as money continued to pour in on the underdog. With the Super Bowl just six days away, the first big Las Vegas sportsbook has made a move to the key number of 4.

According to Vegas Insider, the Westgate SuperBook was dealing Patriots -4 as of 2:52 p.m. on Monday, marking the first time the book has offered the line at 4 for anyone looking to bet the Patriots. The South Point also moved its line to Patriots -4 on Monday. Anyone looking to play the other side could get Eagles +5 at the Golden Nugget on Monday afternoon, but by and large most books had been dealing 4.5 as their line before the Westgate's move to Patriots -4 on Monday.

Moving to -4 is typically a big deal due to the frequency of games historically ending by a four-point margin. However, only nine regular-season games finished with a four-point margin of victory in 2017, fewer than the 13 that ended with a five-point margin of victory.

Get SportsLine's Super Bowl picks from a Patriots expert who's 9-2 in his last 11 picks for or against the team, and from an Eagles expert who's 9-3 in Eagles games and nailed the NFC Championship.    

The Westgate listed the Patriots as -185 on the moneyline along with the drop to 4, with the Eagles available for +155 just to win the game. The total, as it is at most books, remains at 48.

Will -4 be the furthest the line falls before professional bettors start loading up on the Patriots, or will the money coming in on the Eagles necessitate a further tightening of the line? We have about a week to find out.