In comparison to his career averages, batters are swinging at less Papelbon pitches than they have...
In comparison to his career averages, batters are swinging at less Papelbon pitches than they have in the past. Of those pitches, they are more likely to lay off pitches inside the zone than they had in the past. So hitters are being more selective against Papelbon this season.
At the same time, contact rate overall for batters against Papelbon has jumped 8.3% over his career average. The most noticable difference is contact rate outside the strike zone, which has climbed the past two years. While I can't access this data by pitch type, I would strongly suggest that the movement away from the splitter is having an impact here.
Also notable is that Papelbon's overall percentage of balls in the strike zone is down significantly this year. With an 85% plus mix of fastballs, you can surmise his control with the fastball isn't up to previous years' standards. Not only his Papelbon throwing less balls in the zone at large, his first pitch strike % has dipped below 60% compared to previous seasons. Papelbon is working from behind more often than he has in the past. More selective hitters and fewer swings and misses coupled with being behind in the count more often definately points to higher walk rates and a higher WHIP.