Using run differential to find value in MLB's second half
By SCOTT COOLEY
Baseball is a statistics-driven sport. Bettors are constantly searching for the right stat, or combination of, to break the hardball banks.
One stat that is thrown into every oddsmaker’s power rankings equation is run differential. Examining total runs scored by a team against total runs allowed provides the best assessment of a club’s value, despite where it’s stationed in the standings.
"The one stat that I now believe in above all others is run differential,” Washington Post columnist Michael Wilbon said in 2008. “I believe those stats show all around what you're capable of doing."
Below, we take a look at two teams that could excel from a wagering standpoint in the second half of the season based on run differential as well as two that could regress.
*Statistics compiled prior to Friday’s games.
Minnesota Twins (+40 run differential, -2.09 units)
The Twins have fallen back to third place in the AL Central standings but their run differential (RD) indicates they should be the best team in the division. The White Sox hold a RD of +10 while the first-place Tigers have only outscored opponents by seven runs this season.
The other 12 teams in baseball that have a RD of 40 or higher combine for +60.73 units on the year. The average moneyline profit between the dozen is +5.06.
Minnesota is unfortunate to be in the red at this point of the season and bettors should expect a profitable turnaround in the second half. The Twinkies earned 6.16 units post All-Star break in 2009.
Kansas City Royals (-32 RD, +6.11 units)
The Royals have been a surprise to bookies and bettors through the first half of the 2010 campaign. The Boys in Blue have played well under manager Ned Yost, going 27-23 (+11.47 units) since he took over for Trey Hillman.
But Kansas City’s run differential suggests the team has been playing well above its heads. Nine other MLB squads have a RD of -30 or higher and none of them are in the black. In fact, the composite moneyline total of the bottom nine RD teams is -122.69 units.
The Royals will be sellers throughout the trading period and have already been shopping Jose Guillen. Although this is one of the best hitting lineups in baseball from an average standpoint, Kansas City just doesn’t get the job done with runners in scoring position and that will be costly post-break.
St. Louis Cardinals (+52 RD, -10.4 units)
How in the world are the Red Birds double digits in the hole halfway through the season? Well, inflated moneyline losses here and there with Chris Carpenter, Adam Wainwright or Jaime Garcia on the mound are the primary reasons.
The Cardinals are the only team in MLB with a run differential greater than 50 that is in the negative from a betting perspective. St. Louis is also the only squad with the highest RD in its division that isn’t in first place (Reds +49).
Tony La Russa’s clubs are known for being second-half teams. The Cards went 42-29 in the after the break last season and much of the same can be expected this year.
Houston Astros (-116 RD, -3.29 units)
The Astros started the season much like the Nets with everyone calculating projected win totals to see if they would go down in history with their sports’ all-time worst record. But Houston has rebounded a bit over the last two months and should be happy to be just three units down with that horrendous run differential.
Of Houston’s 51 losses, only 11 have come by a margin of one run so playing against the ‘Stros on the runline has been a profitable betting system. The team’s -116 RD is the third-worst in the bigs and the other two teams below that have lost a minimum of nine units.
The Astros brass announced about the third week of the season that everyone was on the trading block. Roy Oswalt will likely be donning another uniform soon while sluggers like Carlos Lee and Lance Berkman could also be on the move. Houston won’t be favored in many games during the second half and they won’t win many either.