Largest Home/Road Splits by OPS in 2007

It seems whenever a Colorado hitter does well, people immediately attribute his success to the altitude at Coors Field. Similarly, players in San Diego get a little benefit of the doubt because Petco Park is one of the better pitcher's parks in the majors. Splits between home games and away games also occasionally come up in trade discussions: for example, Hank Blalock, a better career hitter than the average 3B, is rumored to be on the trading block, but he simply can't hit outside of Texas (.303/.372/.525 in Arlington vs. .243/.301/.398 outside) and so interest among fans, at least, is lukewarm in part because of this (he's also got an injury history).

Regardless, it's always interesting to see how players do in and out of their home park. Conventional wisdom relates that players hit better at home than they do on the road and the MLB splits verify this: in 2007, major league batters put up a .772 OPS at home and a .745 OPS on the road. That's a pretty decent separation.

Let's look at the individual hitters who hit better at home and who hit better on the road. We'll use OPS as the statistic of comparison because it's easy to calculate and pretty useful. The minimum number of total plate appearances might be kind of contentious, but I'm going to pick 300 both because it's a fairly high round number and it breaks up our list into two convenient chunks (what luck!). Twenty-five batters had an OPS at least .200 higher at home than on the road and fifteen had an OPS at least .200 higher on the road than at home.

Largest Difference In Home/Road OPS for 2007

Batters With a .200+ Higher OPS at Home

Details		Home				Away				Difference (Home-Away)
Name	Team	PA	OBP	SLG	OPS	PA	OBP	SLG	OPS	PA	OBP	SLG	OPS
Franklin Gutierrez	CLE	143	.357	.617	.974	158	.282	.343	.625	301	.075	.275	.350
Derrek Lee	CHC	323	.449	.632	1.081	327	.352	.397	.749	650	.097	.235	.332
Frank Catalanotto	TEX	186	.370	.573	.943	191	.305	.317	.622	377	.065	.256	.321
Matt Holliday	COL	363	.435	.722	1.157	350	.374	.485	.860	713	.061	.236	.297
Scott Hatteberg	CIN	212	.436	.571	1.007	205	.351	.366	.717	417	.085	.205	.290
Chone Figgins	LAA	212	.458	.536	.993	291	.346	.359	.705	503	.112	.176	.288
Tony Pena Jr.	KCR	268	.335	.442	.777	268	.234	.271	.505	536	.101	.171	.272
Maicer Izturis	LAA	193	.417	.470	.887	181	.276	.339	.616	374	.140	.131	.271
Corey Patterson	BAL	253	.351	.474	.825	250	.257	.297	.554	503	.094	.177	.271
Jack Cust	OAK	257	.459	.588	1.047	250	.356	.423	.779	507	.103	.165	.268
Aramis Ramirez	CHC	288	.403	.643	1.046	270	.326	.454	.780	558	.077	.189	.266
Nomar Garciaparra	LAD	231	.385	.450	.835	235	.272	.297	.570	466	.113	.152	.265
Ian Kinsler	TEX	276	.398	.523	.921	290	.313	.362	.675	566	.084	.161	.246
Troy Tulowitzki	COL	336	.392	.568	.960	346	.327	.393	.719	682	.066	.175	.241
Esteban German	KCR	188	.382	.469	.851	217	.324	.296	.620	405	.058	.173	.231
Craig Biggio	HOU	328	.314	.446	.760	227	.243	.286	.529	555	.070	.161	.231
Mike Lowell	BOS	323	.418	.575	.993	330	.339	.428	.767	653	.079	.148	.226
Kaz Matsui	COL	216	.381	.482	.864	237	.304	.333	.638	453	.077	.149	.226
Jhonny Peralta	CLE	327	.367	.514	.881	320	.313	.345	.659	647	.053	.169	.222
Pat Burrell	PHI	293	.430	.586	1.016	305	.370	.424	.795	598	.060	.161	.221
Dmitri Young	WSH	232	.414	.568	.982	276	.348	.425	.773	508	.066	.143	.209
Brad Wilkerson	TEX	200	.359	.529	.887	189	.277	.402	.679	389	.082	.126	.208
Juan Uribe	CHW	278	.309	.474	.783	285	.260	.315	.575	563	.049	.159	.208
Kevin Mench	MIL	153	.346	.504	.850	155	.265	.381	.645	308	.082	.123	.204
Marlon Byrd	TEX	224	.406	.510	.916	230	.304	.410	.715	454	.102	.100	.201

Batting Average on Balls In Play (BABIP) is a statistic that measures the amount of hits that fall in. It's formula is (H-HR)/(AB-K-HR+SF); as I'm sure you can tell, by taking out home runs and strikeouts you are left with the at bats where the ball was put in play for the defense to field. Originally applied to pitchers wherein a pitcher with a really high or really low BABIP likely is due for a regression, it can also kind of be used to see if a batter is lucky or not.

Oddly, Juan Uribe's BABIP actually went up when away from US Cellular Field. Since that means more hits were falling in on the road, you'd think his stats would have gone up when on the road. He was the only player to see his BABIP increase; Scott Hatteberg had the largest drop with his BABIP going from .393 at home to .244 on the road.

As I mentioned before, fifteen players had the opposite change in their OPS.

Batters With a .200+ Higher OPS on the Road

Details		Home				Away				Difference (Away-Home)
Name	Team	PA	OBP	SLG	OPS	PA	OBP	SLG	OPS	PA	OBP	SLG	OPS
Wily Mo Pena	BOS/WSH	159	.296	.293	.588	158	.342	.577	.919	317	.046	.284	.330
James Loney	LAD	197	.350	.425	.775	178	.416	.661	1.076	375	.065	.236	.302
Joe Mauer	MIN	237	.326	.336	.663	235	.436	.520	.956	472	.110	.184	.294
John Buck	KCR	199	.256	.350	.606	200	.360	.518	.878	399	.104	.169	.272
Morgan Ensberg	HOU/SDP	162	.280	.310	.589	162	.360	.500	.860	324	.081	.190	.271
Wes Helms	PHI	139	.225	.295	.520	169	.357	.432	.790	308	.133	.137	.269
Luke Scott	HOU	220	.305	.422	.726	205	.400	.593	.993	425	.095	.171	.267
Mike Piazza	OAK	152	.283	.312	.595	177	.339	.500	.839	329	.056	.188	.244
Paul Lo Duca	NYM	243	.263	.310	.573	244	.361	.450	.811	487	.098	.140	.237
Cesar Izturis	CHC/PIT	144	.254	.231	.485	193	.337	.378	.715	337	.083	.146	.230
Albert Pujols	STL	321	.399	.487	.886	358	.455	.642	1.097	679	.057	.155	.211
Alfonso Soriano	CHC	312	.308	.486	.794	305	.367	.636	1.003	617	.060	.150	.209
Shannon Stewart	OAK	296	.311	.319	.629	334	.375	.461	.836	630	.065	.142	.207
Brian Giles	SDP	255	.345	.320	.665	297	.374	.496	.870	552	.029	.177	.205
Moises Alou	NYM	176	.330	.485	.815	184	.451	.566	1.017	360	.122	.081	.202

There aren't really any fluky BABIP stories here. The smallest change was an .019 increase from home to away for Brian Giles and the largest was Luke Scott's .128 jump.

For the curious, the most "even" player in the league in terms of a home/road split in terms of OPS was Greg Dobbs of the Philadelphia Phillies. He hit .275/.324/.456 at home and .268/.335/.444 on the road for a slim .00076 difference in his home (the better one) OPS and road OPS. If, however, you envision a plot of OBP and SLG with OBP on the x-axis and SLG on the y-axis and take the magnitude of the vector that goes to each player's point, you find that Jarrod Saltalamacchia was the closest to having no change. His OBP on the road was .00142 higher than at home and his SLG was .00324 higher at home than on the road.