Fan Graphs pinpoints the reason
for Pirates RH James McDonald’s drastic turnaround from a career 4.00 ERA pitcher to one who currently owns a 2.37 mark this season. His K:BB ratio has also greatly improved from 1.87 career to 3.22 in 2012.
The joint decision between the Pirates staff and McDonald to virtually eliminate his changeup from his arsenal of pitches and add a slider has led to his breakout first half. Fan Graphs details how the slider has become McDonald’s secondary pitch and his most effective in generating swings and misses. They do however caution that a regression could be coming but overall, the 27 year old righty will remain a much improved pitcher.