Exploring the Arsenal will run prior to each game, providing you with a brief scouting report on the starting pitcher expected to oppose the Pirates. The chart below shows the horizontal and vertical movement of every pitch thrown by that particular pitcher in 2012. This chart is from the catcher’s point of view. For a general guide to pitch types for a right-handed pitcher, please check out this image created by Sons of Sam Horn. Graphs are courtesy of Brooks Baseball and The Hardball Times , unless otherwise specified.
| Pitch Types | ||
|---|---|---|
| FA: Four-Seam Fastball | FT: Two-Seam Fastball | FC: Cutter |
| CU: Curveball | SL: Slider | CH: Changeup |
| FS: Splitter | SI: Sinker |
Tuesday, 7:05 PM – Scott Diamond
Diamond has average velocity, with a fastball that sits around 89-91 MPH and tops out at 92. It appears that he throws a four-seamer only, and gets a bit of cutting movement on the pitch. His only breaking ball is a low 80’s slider, and his limited arsenal is rounded out with a low to mid 80’s circle change. He does not really have any above average pitches, and struggles to miss bats with any of his offerings. Diamond has a ground ball rate of 61.4% in 2012, which would rank third in baseball if he had accumulated enough innings to qualify for the leaderboard. Many of those grounders have come on his fastball, which is surprising to me. While the pitch does have a bit more sinking movement than the typical four-seamer, it does not drop as much as the elite sinkers that usually produce that kind of ground ball rate. His changeup has drawn plenty of ground balls this year as well. This has been a large improvement for Diamond from 2011 to 2012, and is a significant reason why he is keeping runs off the board right now. The following chart shows his ground ball rate (ground balls/balls in play) for each pitch type over the past two seasons.
| Year | IP | Fastball | Slider | Changeup | Overall |
|---|---|---|---|---|---|
| 2011 | 39.0 | 48.84% | 41.03% | 50.00% | 46.20% |
| 2012 | 50.2 | 66.95% | 46.15% | 61.54% | 61.40% |
My first thought was that this is most likely the result of a small sample size. Diamond generally posted solid ground ball rates in the minors, but nothing this dramatic. However, he has faced 209 batters so far, and a pitcher’s ground ball rate generally stabilizes in about 150 plate appearances. So I guess it’s possible that he has made a legitimate improvement.
