Jonathan Papelbonphoto © 2009 Keith Allison | more info (via: Wylio)It’s looking good so far, but the Red Sox knew heading into 2011 that Jonathan Papelbon would be pitching for a new deal. It seems to be working so far as Papelbon has been dominant with an ERA of 2.16 and a FIP of 1.85. His xFIP is a bit higher at 3.25, but he has a career HR/FB of 6.7% and could be someone xFIP is poor at measuring.

There is some concern as his velocity is down to the lowest level since becoming a reliever, but it’s still early in the year and velocities are known to increase in the warmer months. The drop in speed hasn’t hurt his effectiveness so far. His K/9 in 8.1 IP stands at 11.88 and while a very small sample that along with a BB/9 of 2.16 are very good signs.

Papelbon came into 2011 planning to throw his slider more and he has. According to Fangraphs.com he is throwing 14.2 percent sliders this year and Texasleaguers.com says 16.7 percent. Both are much higher than the 9 percent he has thrown the past few years.

The interesting thing is his slider is not a very good pitch. In his career it has a run value of -0.40 per hundred sliders thrown. So far this year it only gets a strike 52.2 percent of the time and a swing only 34.8 percent of the time. This isn’t much different from the split-finger he replaced, which also has a run value of -0.41 in his career.

This year though the split-finger is showing a run value of 3.07* so far for every 100 thrown. That will probably come down, but if Papelbon has become more of a three pitch pitcher the hitter can no longer sit on the fastball and pass on the split-finger. His fastball has also been very accurate getting a strike around 75 percent of the time when the league average is 64 percent.

*A positive run value is a good pitch meaning the pitch gives up 3.07 runs less than average for every hundred thrown.

As you can see in the graph below(looking from the first base side) the slider breaks on average right between the fastball and the splitter. The slider also stays at fastball level past the point when hitters must decide to swing.

texasleaguers.com

Here is an overhead graph showing again that the slider moves with the fastball until it breaks away from righties where he has used it 25 percent of the time this year and in on lefties about 15 percent of the time.

texasleaguers.com

It will take more data then we can get in a hole season to see how real this change is and how effective it will be, but it has worked so far. Sometimes using a poor or average pitch more is can be a good thing especially for a reliever currently only using two pitches for the most part. The strikeouts have never been a problem for Papelbon, but the walks have risen each year since 2008. If he can keep hitter of base with the slider and split-finger, but pound the zone with a solid fastball we should see one last year of great closing from him.