Move Over Johan: Mike Pelfrey Is the New Ace of the Staff

Robert Knapel@@RobertKnapel_BRCorrespondent IMay 23, 2010

NEW YORK - MAY 22:  Mike Pelfrey #34 of the New York Mets pitches against the New York Yankees on May 22, 2010 at Citi Field in the Flushing neighborhood of the Queens borough of New York City.  (Photo by Chris McGrath/Getty Images)
Chris McGrath/Getty Images

When the New York Mets traded for Johan Santana, he was supposed to be the staff ace. He was for his first two years on the team.

Santana is still one of the better pitchers in the league, but he has had some struggles recently. Many are hesitant to continue to call him an ace.

Since Santana joined the team, Mike Pelfrey's pitching has significantly improved. Surely, some of it has to do with Santana's mentoring. More of it has to do with Pelfrey coming into his own.

Santana has posed a 3-2 record with a 3.72 ERA through nine starts this year. Pelfrey meanwhile has a 6-1 record with a 2.86 ERA through nine starts. However these are some of the most debated stats when it comes to a pitchers level of success.

If we go and look at some advanced stats we can see that Pelfrey is the true ace of the staff. Since 2008, Santana's strikeout rate has declined from 7.91 K/9 to 7.11 K/9. Pelfrey's strikeout rate has increased from 4.93 K/9 to 6.19 K/9 during that same time period.

Pelfrey has been able to prevent hitters from hitting long balls. Mike allows only .48 HR/9. Compare this to Santana who allows nearly one home run per nine innings (.98 HR/9). This low home run rate is part of what allows Pelfrey to keep the number of runs allowed down.

Batters are hitting .249 with a .289 batting average on balls in play. While Pelfrey has allowed hitters to bat .253, he has been slightly more unlucky has hitters have a .297 batting average on balls in play.

Pelfrey has been able to buckle down better than Santana with runners on base. Pelfrey has left 80.5 percent of men on base while Santana has only left 72.9 percent on base. This is integral to Pelfrey's success. He is able to limit the damage done by other teams by performing under this pressure.

Since ERA is one of the most questioned metrics in baseball, we can take a look at the pitchers xFIP. This is their expected fielding independent ERA. Pelfrey posts a 4.01 xFIP while Santana's xFIP is 4.13.

Another stat we can look at instead of ERA is ERA+. In this case, the higher the better. Pelfrey has an ERA+ of 142 and Santana has an ERA+ of 112.

Pelfrey is clearly a pitcher who is improving. Santana appears to be on a slight decline. By the end of the year it should be obvious: Pelfrey will be the ace of the staff.

This will most likely be debated due to Santana's past, but when you look at all the facts, Mike Pelfrey is the best pitcher the Mets have.