St. Louis Cardinals vs. Chicago Cubs: Odds, Analysis, MLB Betting Pick

The Chicago Cubs (49-45) will look to extend their winning streak to seven games when they host the St. Louis Cardinals (46-49) as home favorites at the sportsbooks for the series opener Friday.

The Cubs hope to continue their charge toward first place in the National League Central, as they trail the division-leading Milwaukee Brewers, who have lost five in a row, by only one game now.

Betting line: The Cubs opened as -160 favorites (wager $160 to win $100), according to sportsbooks monitored by OddsShark. (Line updates and matchup report)

MLB betting pick, via OddsShark computer: 5.6-3.4, Cubs (MLB picks on every game)

Why the Cardinals can pay on the MLB lines

While Chicago has gotten off to a blazing start to the second half of the season, all six of the team's wins during the streak have come on the road. The Cubs may be a bit overconfident heading back home for this key series, especially since the Cardinals have struggled a bit lately.

St. Louis is coming off a four-game split with the New York Mets that saw the squad drop the final two. Before that, the Cards won five of seven.

Why the Cubs can pay on the MLB lines

Chicago will give the ball to Jake Arrieta (9-7, 4.17 ERA) at Wrigley Field, and he has pitched pretty well there this year. He is 3-1 with a 4.01 ERA in six home starts, with opposing batters hitting only .227 against him.

Arrieta is coming off a road victory against the Baltimore Orioles last Saturday, having allowed one earned run and four hits in 6.2 innings with three walks and three strikeouts. If he can pitch like that again in this spot, the Cubs should be able to keep their winning streak rolling in the right direction.

Smart betting pick

Again, it may seem easy to keep backing Chicago as a relatively small home favorite, but this is a rivalry game with St. Louis coming to the Windy City as a live underdog.

Arrieta's counterpart, Carlos Martinez (6-8, 3.36 ERA), has seen the Cardinals lose his last five starts, but he has allowed just two runs in three of them.

Even though they have lost six of the past eight meetings with the Cubs, according to the OddsShark MLB Database, take a shot with Martinez and St. Louis to pull off the road upset.

MLB betting trends

The total has gone under in seven of St. Louis' last nine games.

The total has gone under in five of St. Louis' last seven games on the road.

Chicago is 5-1 in its last six games when playing at home against St. Louis.

All MLB lines and betting trends courtesy of Bleacher Report’s official odds partner, OddsShark. All quotes gathered firsthand unless otherwise noted. Check out Twitter for injury and line-movement updates and the OddsShark YouTube page for picks and analysis, or download the free odds tracker app.