Jonathan Sanchez's BB/9

As a follow-up to my recent article on Jonathan Sanchez: Ross of Ross and the Heckler Speak suggested that there is still hope Sanchez can become an elite arm, citing Randy Johnson as an example. Johnson, as you might know, didn't truly become "elite" until age 29, when he suddenly began to walk batters at a much lower rate.

I wanted to see if there have been more pitchers, in the past, that have been able to shake their bad BB/9 habits at age 28 (or older). (I set 28 as the cut-off, because Johnson made the leap after his age-28 season, and Sanchez is currently 28.)

Here are the expansion-era starters who have had a BB/9 above 4.5 from ages 20-28 (min. 600 IP):

Rk	Player	BB/9	IP	From	To	Age	G	GS	ERA+
1	Bobby Witt	6.11	1173.0	1986	1992	22-28	191	188	89
2	Jason Bere	5.85	661.1	1993	1999	22-28	130	122	86
3	Randy Johnson	5.71	818.0	1988	1992	24-28	130	129	101
4	Nolan Ryan	5.43	1647.2	1968	1975	21-28	253	220	112
5	Daniel Cabrera	5.24	892.1	2004	2009	23-28	162	155	88
6	Dave Morehead	5.09	819.1	1963	1970	20-27	177	134	90
7	Oliver Perez	5.08	1111.2	2002	2010	20-28	206	195	91
8	Shawn Estes	4.74	990.0	1995	2001	22-28	160	160	98
9	J.R. Richard	4.74	1200.0	1971	1978	21-28	183	166	100
10	Steve Dunning	4.74	613.2	1970	1977	21-28	136	84	82
11	Ryan Dempster	4.72	1076.2	1998	2005	21-28	247	162	88
12	Shawn Chacon	4.69	740.1	2001	2006	23-28	190	115	95
13	Tom Griffin	4.66	933.2	1969	1976	21-28	210	134	86
14	Mike Torrez	4.60	1259.0	1967	1975	20-28	209	185	100
15	Jonathan Sanchez	4.59	617.1	2006	2011	23-28	157	101	101
16	Jimmy Haynes	4.59	894.2	1995	2001	22-28	170	147	83
17	Russ Ortiz	4.56	924.2	1998	2002	24-28	154	144	102
18	Balor Moore	4.56	644.0	1972	1979	21-28	143	93	89
19	Blue Moon Odom	4.56	1299.1	1965	1973	20-28	223	202	97
20	Jamey Wright	4.54	1055.2	1996	2003	21-28	178	175	94
21	Joe Sparma	4.54	864.2	1964	1970	22-28	183	142	87
22	Joe Decker	4.50	624.2	1969	1975	22-28	130	91	98
23	Mike Kekich	4.50	739.1	1965	1973	20-28	171	110	72

Provided by Baseball-Reference.com: View Play Index Tool Used
Generated 4/10/2011.

Now here's what those pitchers did after the age of 28:

Just five of those 22 pitchers (not including Sanchez, of course) managed to bring their BB/9 below four over the rest of their career. Five of them didn't even pitch after age 28, and just four managed an ERA+ over 100 post-28. J.R. Richard, Randy Johnson, and Ryan Dempster were able to bring down their BB/9 significantly, resulting in a boost in their status to what we would consider great -- though Dempster's SIERA has never been below 3.70, which is what Sanchez posted in 2010. Of course, if we're going by ERA+, Sanchez's ERA+ in 2010 was 133, which is already great (though quite  inflated, as fielding-independent stats indicate).

Now it's not entirely fair, because only a few of these pitchers had K rates above 8.0 (Sanchez's is above 9, of course). Those pitchers were: Nolan Ryan, Bobby Witt, Randy Johnson, and Oliver Perez.  Ryan had the same ERA+ up until age 28 as he did after age 28. Witt (whose K/9 was quite lower than Sanchez's -- but still above eight) failed to bring his BB/9 below four post-28, and was essentially slightly-below-average over the rest of his career. Johnson was the only one of these four to make that jump to elite status, and Oliver Perez's career is basically over now at the age of 29, as he's rapidly declined.

So what do we get from all of this? It is, in actuality, possible that Sanchez does develop into an elite arm. The one thing he has going for him is his extremely high K/9, which is quite a rarity. The truth is, Sanchez is quite a unique specimen, so it's not exactly easy to find comparisons for him.

However, while it's possible for him to significantly lower his BB/9 at this point in his career, it's against the odds. Pitchers who have had Sanchez's BB/9 habits up until the age of 28 have not generally been able to bring it back down to earth.

My expectations for Sanchez are as follows: he's clearly a great pitcher, and that will likely be the case over his next (and possibly final) two years with the Giants. But I don't think he'll ever manage an SIERA below three over the course of a full season (Randy Johnson's was as low as 1.69 in 2001, by the way). His BB/9 is preventing him from becoming an elite arm, and he likely won't overcome this problem.

-- I would also note that of all the pitchers here, Johnson is most comparable to Sanchez because of the high K and BB rates up until age 28. So that's certainly reason for optimism. --

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