Comparing April Velocites to April 2012 Velocities
Last week I looked at early season velocity gainers and losers. It was noted that the average fastball velocity so far is down league wide from where it was in 2012 but fairly consistent with the average fastball velocity in April 2012. But some commenters suggested that it might be useful to look at the April 2012 velocities of the guys who have seen the biggest gains and losses in velocity this year. The idea is to see if the discrepancy between 2012 velocities and April 2013 velocities is an indication of a change or just evidence that a guy tends to see his velocity dip or rise at the beginning of the year.
To gather a sample, I created a list of guys who threw 150+ innings last year and who had at least 20 innings this April. That yielded me a list of 70 pitchers. To find the significant changes in velocity, I calculated the differences in average fastball velocity between all of 2012 and April 2013. I then calculated the average difference and standard deviation to see who had made the biggest changes. Below are the guys who saw the biggest gains in velocity in April. Read the rest of this entry »