So far most of the pitchf/x analysis has focused on the pitcher, but each at-bat says just as much about a hitter as it does a pitcher. Thus, the pitchf/x data offers a wealth of information about batters that is currently underutilized. There have been some exceptions: Max Marchi's look at how the location in the zone of a hit pitch correlates with the location in the field of the resulting ball in play and Josh Kalk's look at how different hitters respond to first pitch fastballs. There have also been some great pitchf/x analyses of individual hitters: Jeremy's look at Micah Owings as a hitter, Trip Somers' look at Nelson Cruz's plate discipline and Mike Fast's examination of Jack Cust's performance against fastballs. In this post I want to continue this application of pitchf/x data to hitter analysis.

You often hear certain hitters referred to as 'fastball hitters.' I wanted to see if this is justified. Is there a certain subset of batters who do particularly well against fastballs? The stereotype is that fastball hitters are high strikeout, HR hitters. Is this the case? More generally, what can we say about the offensive performance of good fastball hitters versus good non-fastball hitters.

For every hitter in the pitchf/x database I found the average run value for all fastballs and all non-fastballs thrown to him during part of 2007 and all of 2008 (the pitchf/x system was added incrementally to different ballparks during the 2007 season). Here are the leaders and laggards:

+-------------------+--------+------------+-------------------+--------+------------+
| Name              | num FA | FA run val | Name              |num nFA |nFA run val |
+-------------------+--------+------------+-------------------+--------+------------+
| Albert Pujols     |   1973 |     0.0348 | Jody Gerut        |    412 |     0.0332 |
| Shin-Soo Choo     |    813 |     0.0313 | Lance Berkman     |   1284 |     0.0329 |
| Mark Teixeira     |   2657 |     0.0260 | Manny Ramirez     |   1351 |     0.0311 |
| Chipper Jones     |   2068 |     0.0251 | Magglio Ordonez   |   1121 |     0.0309 |
| Jack Cust         |   2337 |     0.0229 | Chris Davis       |    480 |     0.0298 |
| Alfonso Soriano   |   1545 |     0.0223 | Vladimir Guerrero |   1525 |     0.0290 |
| David Ortiz       |   1938 |     0.0217 | Milton Bradley    |    891 |     0.0272 |
| Josh Hamilton     |   1687 |     0.0217 | Nomar Garciaparra |    708 |     0.0261 |
| Carlos Quentin    |   1242 |     0.0215 | Alex Rodriguez    |   1147 |     0.0258 |
| Ryan Howard       |   2030 |     0.0210 | Matt Holliday     |   1178 |     0.0213 |
+-------------------+--------+------------+-------------------+--------+------------+
| Omar Vizquel      |   1227 |    -0.0178 | Craig Monroe      |    564 |    -0.0162 |
| Nomar Garciaparra |    936 |    -0.0180 | John McDonald     |    495 |    -0.0167 |
| Jose Molina       |    894 |    -0.0199 | Brad Ausmus       |    427 |    -0.0171 |
| Carlos Gonzalez   |    625 |    -0.0204 | Adam Kennedy      |    534 |    -0.0176 |
| Chris Burke       |    892 |    -0.0205 | Brandon Inge      |   1062 |    -0.0179 |
| Tony Pena         |    894 |    -0.0218 | Jacque Jones      |    605 |    -0.0180 |
| John McDonald     |   1026 |    -0.0236 | Yorvit Torrealba  |    715 |    -0.0204 |
| Omar Quintanilla  |    638 |    -0.0260 | Endy Chavez       |    429 |    -0.0230 |
| Andy LaRoche      |    686 |    -0.0261 | Corey Patterson   |    653 |    -0.0267 |
| Wily Mo Pena      |    549 |    -0.0290 | Tony Pena         |    504 |    -0.0348 |
+-------------------+--------+------------+-------------------+--------+------------+

Of course the leaders of both lists are going to be amazing hitters, this is almost by definition since we searched for the best fastball and non-fastball hitters. But there are some interesting names among the leaders, with Shin-Soo Choo surprisingly the second best fastball hitter in the pitchf/x era. Amazingly Jody Gerut was the best non-fastball hitter. Nomar Garciaparra was a great non-fastball hitter and a horrid fastball hitter. The laggards are mostly no-hit middle infielders and catchers. Tony Pena and John McDonald, mercilessly, end up on both laggard lists.

About 60% of pitches thrown are fastballs so the overall performance (against all pitches) of the best fastball hitters should be better than the overall performance of the best non-fastball hitters. That is the case: they have a higher walk rate (13% versus 11%), a higher HR per fly rate (21% versus 17%) and a higher OPS (.942 versus .920). The non-fastball hitters strike out less (16% versus 18%) and have a higher batting average of balls in play (.337 versus .322). This begins to bear out the stereotype that fastball hitters tend to be high K, high HR hitters. But I don't consider Albert Pujols a fastball hitter, he is an all around amazing hitter. I think a better metric of "fastball hitterness" is the difference between the average run value of fastballs and a non-fastballs thrown to a given hitter. Here are the leaders (perform better versus fastballs) and laggards (perform better against non-fastballs) for this metric.

+-------------------+--------+------------+------------+------------+
| Name              |    num | run val FA |run val nFA |        dif |
+-------------------+--------+------------+------------+------------+
| Shin-Soo Choo     |   1369 |     0.0313 |     0.0004 |     0.0309 |
| Jack Cust         |   4224 |     0.0229 |    -0.0027 |     0.0256 |
| Gary Matthews     |   3209 |     0.0099 |    -0.0144 |     0.0242 |
| Brandon Moss      |   1067 |     0.0069 |    -0.0149 |     0.0218 |
| Travis Hafner     |   2060 |     0.0089 |    -0.0128 |     0.0217 |
| Brian Schnieder   |   1662 |     0.0059 |    -0.0153 |     0.0212 |
| Reed Johnson      |   2101 |     0.0089 |    -0.0123 |     0.0211 |
| Michael Young     |   4299 |     0.0097 |    -0.0113 |     0.0211 |
| Chris Young       |   3910 |     0.0107 |    -0.0093 |     0.0200 |
| Jason Bay         |   3378 |     0.0164 |    -0.0031 |     0.0196 |
+-------------------+--------+------------+------------+------------+
| Mike Jacobs       |   2296 |    -0.0045 |     0.0198 |    -0.0243 |
| Austin Kearns     |   1859 |    -0.0126 |     0.0121 |    -0.0247 |
| Willie Bloomquist |   1295 |    -0.0128 |     0.0133 |    -0.0261 |
| Clint Barmes      |   1505 |    -0.0100 |     0.0171 |    -0.0271 |
| Kenji Johjima     |   2718 |    -0.0174 |     0.0103 |    -0.0277 |
| Omar Infante      |   1441 |    -0.0139 |     0.0156 |    -0.0295 |
| Chirs Davis       |   1143 |     0.0001 |     0.0298 |    -0.0297 |
| Omar Quintanilla  |   1012 |    -0.0260 |     0.0039 |    -0.0300 |
| Jody Gerut        |   1249 |    -0.0005 |     0.0332 |    -0.0337 |
| Nomar Garciaparra |   1644 |    -0.0180 |     0.0261 |    -0.0442 |
+-------------------+--------+------------+------------+------------+

A casual glance confirms our picture of fastball hitters as high strikeout, high power guys (Chris Davis seems really out of place among the non-fastball hitters). But it is hard to make any conclusions about what fastball hitters are like generally because fastball hitters are on average better hitters (since most pitches are fastballs). The measure of fastball hitterness (average fastball run value minus average non-fastball run value) is positively correlated with almost any offensive measure: HR per fly, BB rate, OBP, SLG, wOBA, BABIP, LD%. What I need to do is compare fastball hitters against non-fastball hitters who are just as good, and see in what respects they differ.

In order to make this comparison I am going to look at the relationship between a hitter's fastball run value minus non-fastball run value and a number of offensive metrics (K rate, HR per fly, BABIP, BB rate, GB%, LD%) relative to the hitter's overall offensive level. I use wOBA as my measure of a hitter's offensive level (wOBA, another TangoTiger creation, is one of the best metrics of a player's offensive value). The first thing to do is find the linear relationship between wOBA and all these measures (it is positively correlated with just about any meaningful offensive metric). Then for each batter I look at the difference between his value for a given measure and that expected based on his wOBA. This gives the hitter's performance for that measure relative to his overall offensive level.

An example would be helpful. The graph below displays the relationship between wOBA and walk rate. Generally the more a player walks the higher his wOBA, as you can see by the trend line I drew in. For each hitter I calculate the residual, which is how much more or less that player walks compared to his wOBA peers. The red line is the residual for Jermaine Dye. He walked 3.4% less than expected based on his wOBA, so his residual is -0.034. The blue line is Gregor Blanco who walked much more than his wOBA would suggest, so his residual is 0.059. The green dot is Carlos Quentin. His residual is just below zero.

These residuals tell me if a player gets a greater than average amount of his offensive value from walks (like Blanco), or on the other hand if he gets less value from walks and gets his excess value elsewhere (like Dye does with his power). I calculated these residuals for all the offenses measure mentioned above. Now I am ready to see if fastball hitters get their value from walks, home runs, avoiding strikeouts (contact skills), having a high BABIP, or anything else by seeing the how my "fastball hitterness" correlates with each of these residuals.

The results confirm our initial assumptions. There is a strong positive correlation between fastball run value minus non-fastball run value and the HR per fly, BB% and K% residuals. So hitters who perform better against fastballs than non-fastballs hit more HRs, take more walks and strikeout more than the average hitter of the same offensive level. Fastball hitters tend to be power hitters. This would suggest that pitchers should throw fewer fastballs to power hitters, which is exactly what they do. It seems MLB pitchers knew all of this already, but I am happy to confirm for them.