Andy Pettitte Projections and Statistics of Older Pitchers

The blog's first attempt to find historical context for Andy Pettitte's comeback found that there is not much precedent for a pitcher doing what Pettitte is attempting, which is for an older pitcher to have a productive season, retire, then come back after a year off. This post will look at some examples of older pitchers' performance in recent years.

For context, the projection systems Marcels, ZiPS, and Steamers project Andy Pettitte will pitch in the range of 73-125 IP, with an ERA ranging from 4.01 to 4.45. These are reasonable projections for Pettitte's regular-season performance. While these projections represent serviceable performance, I am hoping for more - 160 IP and performance above league average.

The following table gives examples that show the range of possibilities. The table lists shows the innings pitched and ERA of each pitcher since Andy started pitching in 1995 who 39 or older and pitched at least 100 innings in a season. Only relatively recent seasons were included in case there are any variables in this era that impact pitcher longevity. To provide context, each row also shows the pitcher's ERA+:

Name	Year	Age	IP	ERA	ERA+
Brown, Kevin	2004	39	132.0	4.09	111
Candiotti, Tom	1997	39	135.0	3.60	109
Candiotti, Tom	1998	40	201.0	4.84	92
Clemens, Roger	2002	39	180.0	4.35	103
Clemens, Roger	2003	40	211.7	3.91	114
Clemens, Roger	2004	41	214.3	2.98	148
Clemens, Roger	2005	42	211.3	1.87	228
Clemens, Roger	2006	43	113.3	2.30	195
Darwin, Danny	1996	40	164.7	3.77	125
Darwin, Danny	1997	41	157.3	4.35	100
Darwin, Danny	1998	42	148.7	5.51	73
Fassero, Jeff	2004	41	112.0	5.46	88
Finley, Chuck	2002	39	190.7	4.15	101
Glavine, Tom	2005	39	211.3	3.53	117
Glavine, Tom	2006	40	198.0	3.82	115
Glavine, Tom	2007	41	200.3	4.45	98
Hernandez, Orlando	2005	39	128.3	5.12	88
Hernandez, Orlando	2006	40	162.3	4.66	99
Hernandez, Orlando	2007	41	147.7	3.72	117
Hershiser, Orel	1998	39	202.0	4.41	91
Hershiser, Orel	1999	40	179.0	4.58	98
Johnson, Randy	2003	39	114.0	4.26	109
Johnson, Randy	2004	40	245.7	2.60	174
Johnson, Randy	2005	41	225.7	3.79	113
Johnson, Randy	2006	42	205.0	5.00	92
Johnson, Randy	2008	44	184.0	3.91	119
Jones, Doug	1999	42	104.0	3.55	129
Leiter, Al	2005	39	142.3	6.13	68
Maddux, Greg	2005	39	225.0	4.24	104
Maddux, Greg	2006	40	210.0	4.20	112
Maddux, Greg	2007	41	198.0	4.14	97
Maddux, Greg	2008	42	194.0	4.22	92
Martinez, Dennis	1995	40	187.0	3.08	155
Martinez, Dennis	1996	41	112.0	4.50	110
Morgan, Mike	1999	39	140.0	6.24	82
Morgan, Mike	2000	40	101.7	4.87	100
Moyer, Jamie	2002	39	230.7	3.32	131
Moyer, Jamie	2003	40	215.0	3.27	132
Moyer, Jamie	2004	41	202.0	5.21	86
Moyer, Jamie	2005	42	200.0	4.28	97
Moyer, Jamie	2006	43	211.3	4.30	105
Moyer, Jamie	2007	44	199.3	5.01	92
Moyer, Jamie	2008	45	196.3	3.71	119
Moyer, Jamie	2009	46	162.0	4.94	86
Moyer, Jamie	2010	47	111.7	4.84	84
Mulholland, Terry	2004	41	123.3	5.18	92
Mussina, Mike	2008	39	200.3	3.37	133
Rogers, Kenny	2004	39	211.7	4.76	105
Rogers, Kenny	2005	40	195.3	3.46	134
Rogers, Kenny	2006	41	204.0	3.84	119
Rogers, Kenny	2008	43	173.7	5.70	79
Schilling, Curt	2006	39	204.0	3.97	121
Schilling, Curt	2007	40	151.0	3.87	124
Smoltz, John	2006	39	232.0	3.49	129
Smoltz, John	2007	40	205.7	3.11	140
Wakefield, Tim	2006	39	140.0	4.63	103
Wakefield, Tim	2007	40	189.0	4.76	101
Wakefield, Tim	2008	41	181.0	4.13	114
Wakefield, Tim	2009	42	129.7	4.58	103
Wakefield, Tim	2010	43	140.0	5.34	82
Wakefield, Tim	2011	44	154.7	5.12	84
Wells, David	2002	39	206.3	3.75	119
Wells, David	2003	40	213.0	4.14	107
Wells, David	2004	41	195.7	3.73	104
Wells, David	2005	42	184.0	4.45	102
Wells, David	2007	44	157.3	5.43	76
Williams, Woody	2006	39	145.3	3.65	112
Williams, Woody	2007	40	188.0	5.27	84

There are some clunkers on this list- though mostly for pitchers well into their 40s. And this list has a selection bias - only pitchers who were both deemed worthy of an opportunity to pitch often and whose bodies were able to hold up make this list.

However, clearly a pitcher can still be very effective at age 39 and above. 31 of the 68 pitchers met both of the criteria for which I was looking (above-league-average ERA+and 160 IP). And ERA+ indicates most of these pitchers performed above league average. Of course is not breaking news that older pitchers can have good, late-career seasons. Rather, it just strikes me as interesting to eyeball  specific, actual pitchers' seasons that show the potential upside for the Yankees and Andy Pettitte.