Pitching to the score

You often hear pitchers talk about how they pitch to the score. That is, they do their best pitching when the game is close and let up somewhat when their team gives them a big lead. Jack Morris, for example, has said on a number of occasions that the reason for his relatively high career ERA (3.90) was that he pitched to the score. He says he was more interested in getting wins and pitching deep into games than he was about his ERA and that he would give up a lot of his runs in games where his team had built up a big lead. I don't doubt that pitchers pitch differently according to the situation but how much does it affect their actual performance?

A few years ago, Joe Sheehan at Baseball Prospectus examined Morris' claim in "The Jack Morris Project". He tracked every inning of Morris' career and looked at his performance in different game situations - ties, one run leads, six run leads, etc. Joe did not find that Morris pitched much better in close games than he did with big leads. He did however, admit that he was not really sure what a pitcher's performance would look like if he actually did pitch to the score.

My goal here is to expand upon Sheehan's project by looking at a large group of pitchers rather than just one. From that, I should be able to get a better idea of what pitching to the score looks like and which pitchers have such a tendency. An example of how the analysis works is this: If a starting pitcher begins an inning with a two run lead, his runs allowed during that inning go into the "up by two runs" category. Using the retrosheet databases, I looked at every inning pitched by every starting pitcher between 1990 and 2007 (excluding 1999 because the data were not available that year). The results are shown in Table 1 below.

Table 1: MLB ERA by Score - 1990-2007 (excluding 1999)

	Total	Up 7+	Up 6	Up 5	Up 4	Up 3	Up 2	Up 1
IP	460,868	12,270	7,770	12,361	19,151	29,278	43,883	65,792
ERA	4.45	4.57	4.60	4.73	4.49	4.51	4.31	4.33

	Tied	Down 1	Down 2	Down 3	Down 4	Down 5+
IP	165,728	49,910	29,090	15,201	6,822	3,612
ERA	4.39	4.37	4.63	4.89	4.77	5.69

You can see that the overall ERA for starting pitchers was 4.45 and you should also notice that the lowest ERAs do indeed come in innings where the margin is small: 4.39 in tie games, 4.33 when up by one run, 4.37 when down by one run, etc. The worst ERAs occur in innings where the pitchers are behind by a significant margin: 4.89 when down by three, 4.77 when down by four, etc. That should be expected though because a pitcher who is behind by a lot of runs must not have been pitching well prior to the inning and would tend to continue to struggle going forward. More interestingly, the ERAs in innings where pitchers had big leads were also relatively high: 4.73 with five run leads, 4.60 with six run leads, etc.

Table Two presents annual data comparing the performance of pitchers in close games (tied, down by one, up by one) and blow outs (leading by five or more runs). I computed a ratio as follows:

(ERA in close games/ERA in blow outs) X 100

A ratio of 100 would mean that pitchers performed the same in innings where the margin was small as in innings where they had big leads. A ratio under 100 would indicate that they did better with when the score was close, whereas a ratio of over 100 would indicate a better ERA in innings beginning with a large lead.


Table 2: MLB ERA - Up by five runs versus within one run

year	total ip	total ERA	IP up 5+ runs	ERA up 5+ runs	IP within 1 run	ERA within run	ratio
Total	460,868	4.45	32,401	4.64	281,430	4.37	94
1990	25,521	3.97	1,718	3.99	15,783	3.99	100
1991	25,587	4.02	1,775	4.20	16,013	3.97	94
1992	26,098	3.85	1,528	4.18	16,643	3.75	90
1993	27,730	4.26	1,840	4.56	17,075	4.20	92
1994	19,472	4.55	1,506	4.53	11,699	4.49	99
1995	23,907	4.53	1,783	4.87	14,365	4.48	92
1996	27,006	4.73	2,017	5.18	16,248	4.57	88
1997	27,168	4.45	1,897	4.67	16,590	4.38	94
1998	29,466	4.55	2,093	5.00	18,094	4.40	88
2000	28,756	4.86	2,253	5.07	17,117	4.79	95
2001	28,774	4.57	2,045	4.73	17,536	4.41	93
2002	28,761	4.40	2,091	4.29	17,637	4.37	102
2003	28,616	4.52	2,094	4.61	17,165	4.48	97
2004	28,437	4.62	1,946	4.67	17,239	4.58	98
2005	29,138	4.36	1,897	4.45	17,983	4.33	97
2006	28,295	4.69	2,046	4.77	17,082	4.59	96
2007	28,135	4.62	1,872	4.77	17,162	4.54	95

Using 2007 as an example, we get (4.54/4.77) x 100 = 95. That means that pitchers pitched 5% better in close games than in blow outs. Averaging across all 17 years in the study, pitchers did 6% better in close games.

Next, I looked at individual pitchers and that's why I included so many years in the study. Just looking at one year or a couple years of data wasn't going to work because the sample size for innings pitching with a lead of five or more runs would be too small. So, for this part of the analysis, I selected 23 pitchers with 2,000 or more innings pitched during the period. These data are in Table 3 below.

Table 3: Individual pitcher ERA - Up by five runs versus within one run

First	Last	total ip	total ERA	IP up 5+ runs	ERA up 5+ runs	IP within 1 run	ERA within run	ratio
John	Smoltz	2,648	3.33	161	4.18	1,515	3.25	78
Andy	Benes	2,222	3.84	186	4.45	1,343	3.55	80
Steve	Trachsel	2,254	4.21	145	4.95	1,467	4.04	81
Tom	Glavine	3,684	3.37	321	4.01	2,186	3.39	85
Kevin	Brown	2,837	3.31	163	3.87	1,717	3.35	87
Kevin	Appier	2,342	3.55	167	4.32	1,471	3.76	87
Tim	Wakefield	2,256	4.34	189	4.75	1,343	4.16	88
Roger	Clemens	3,443	3.06	242	3.39	2,046	3.04	90
David	Wells	2,935	4.13	309	4.17	1,714	3.77	91
Randy	Johnson	3,370	3.22	289	3.20	1,976	2.95	92
Jack	Morris*	3,746	3.90	327	4.46	2,169	4.15	93
Greg	Maddux	3,921	2.97	296	3.13	2,387	2.93	94
Livan	Hernandez	2,168	4.22	175	4.48	1,281	4.23	94
Andy	Pettitte	2,320	3.77	220	3.52	1,349	3.45	98
Jamie	Moyer	2,658	4.18	259	4.16	1,500	4.15	100
Mike	Mussina	3,155	3.71	302	3.70	1,864	3.72	101
Curt	Schilling	2,882	3.40	242	3.31	1,685	3.33	101
Kevin	Tapani	2,083	4.33	158	4.00	1,227	4.08	102
Chuck	Finley	2,453	3.85	203	3.72	1,450	3.81	102
John	Burkett	2,467	4.24