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Saturday, August 07, 2004

The Four Man Rotation Redux

On my recent vacation in Florida I had a chance to pick up The Neyer/James Guide to Pitchers. Wow! In addition to providing an entertaining (if brief) history of pitching followed by histories of each pitch and biographies of some underrated pitchers Rob Neyer and Bill James provide an encyclopedia of what pitchers threw. So, for example if you want to know what Fergie Jenkins threw you can flip to his entry and see the following:

"Pitches: 1. Four-Seam Fastball 2. Two-Seam Fastball 3. Slider 4. Curve 5. Forkball (as change)"

They then document the source of this info along with quotes from other sources about the style or way in which the pitcher threw. Absolutely fascinating - a must have for those interested in baseball history and particularly for those who love pitching. . BTW, I see that Neyer has now published some errata for the book.

Pitcher Abuse?
The only controversial aspect of the book and topic that has been hot in the sabermetric community as of late is an essay by James called "Abuse and Durability" and a rebuttal by Rany Jazayerli and Keith Woolner from Baseball Prospectus titled "A Response in Defense of PAP" (I blogged briefly about PAP (pitcher abuse points) recently). These essays reflect James' criticism of the methodology used by Jazayerli and Woolner and their response. In short, James uses a set of comparison studies to compare pitchers marked as abused by PAP against other pitchers and tries to determine how the value of each set of pitchers changes over time. He concludes that the "pitchers that Jazayerli and Woolner identify as 'abused' declined in value by 10% in the following season. That can't possibly be an unnatural decline. This system simply does not identify at-risk pitchers, period." [emphasis in the original]

This idea that pitchers could be abused and the modern emphasis on pitch counts can be traced to the work of one-time sabermetrician for the Texas Rangers Craig Wright in his book The Diamond Appraised as well as to James himself in the early Baseball Abstracts (in 1982 he discusses Billy Martin's pattern of abuse). In fact, James quotes Wright's book in criticizing PAP. I pulled out my copy (no sabermetric library should be without one) and recalled that Wright did his study based on what he called Estimated Batters Faced Per Start (BFS) calculated as:

BFS = ((IP * 3) + H + BB) / ((GS + ((G-GS) * .5)))

Wright then identified those pitchers with high BFS numbers at young ages to see how their careers progressed versus other pitchers with low BFS values at similar ages (typically 18-24). After doing his comparison study on pitchers with high BFS numbers in the teens versus those who were not worked as hard Wright lays out the following guidelines for pitcher use (p211):

"1. As a teenager, a pitcher should not be allowed to throw two-hundred innings seasons or have a BFS over 28.5 in any significant span (150-plus innings)."
2. A teenage pitcher should not start on three days rest..."
3. For ages twenty to twenty-two, they should average no more than 105 pitches per start for the season (105 pitches is the rough equivalent of a 30.0 BFS). A single game ceiling should be set at 130 pitches.
4. For age twenty-three to twenty-four, the restraints can be eased up, but their season average should stay under 110 pitches in most cases. The single game ceiling can be jumped to 140 as long as the pitcher is still strong."

To Wright it is clear that the age of the pitchers is the crucial element coupled with the average number of pitches over a prolonged period as well as the maximum number of pitches in a start. It is this crucial fact that James points out when he says "Craig was concerned mostly with the effect of hard usage on young pitchers." [emphasis in the original]. Although James calls the omission of a strong age component a "marginal concern" in the PAP system it appears to me to be the central reason why James doesn't detect abuse. His studies simply look at the list of pitchers selected as most abused by the PAP system which consist of pitchers of all ages, many of whom since they are mature, aren't really impacted by high pitch counts as discussed in this interesting article on mlb.com by Will Carroll.

Adjustments for age have been made to PAP since 2001 as pointed out in the rebuttal but James downplays their importance in his criticism. Woolner and Jazayerli, however, in defending their work say that "Bill is almost certainly right when he states that almost all of the risk inherent in throwing too many pitches occurs in a pitcher's formative years. The connection between overuse and catastrophic injury seems to drop off quickly past age 25 or so." The PAP system, however, still includes all pitchers and so likely "labels" some pitchers as abused who are mature and can handle the work load.

Checking For Abuse
Because Wright performed his study in the late 1980s I wanted to check and see if his recommendations had been followed so I ran some queries to test points 1,3, and 4.

To test point (1) I ran a query showing those teenage pitchers with 200 inning seasons or a BFS over 28.5 in 150 innings or more since 1960 (of course now that batters faced is known I did not need to rely on Wright's formula). The only two pitchers that match these criteria since 1960 were a pair of 19 year olds - Gary Nolan for the Reds in 1967 (226 IP and BFS of 29.1) and Wally Bunker in 1964 for the Orioles (214 IP, 29.3 BFS). Nolan's arm injury is well known although Bunker also developed a sore arm in 1965 and was never the same winning only 41 more big league games. The sample size is too small to say anything definitive of course.

To test point (3) I ran a query showing those pitchers who threw more than 105 pitches per start using Tangotiger's basic pitch count estimator (3.3*((IP * 3) + H + BB))+(1.5*SO)+(2.2*BB) but replacing (IP*3)+H+BB with actual batters faced) at ages 20 through 22 (as of July 1) in over 30 starts since 1960. There were 51 seasons that qualified.



Name            Year   Age         GS     IP           BFS     P/GS

--------------- ------ ----------- ------ ------------ ------- -------
Jose Rijo 1986 21 26 193.7 32.9 127.9
Mark Fidrych 1976 21 29 250.3 34.3 122.4
Bert Blyleven 1973 22 40 325.0 33.0 122.3
Frank Tanana 1975 21 33 257.3 31.2 120.0
Frank Tanana 1974 20 35 268.7 32.2 118.8
Vida Blue 1971 21 39 312.0 30.9 118.7
Dwight Gooden 1986 21 33 250.0 30.9 116.4
Don Gullett 1973 22 30 228.3 31.4 116.3
Dwight Gooden 1985 20 35 276.7 30.4 116.2
Jon Matlack 1972 22 32 244.0 31.3 116.2
Fernando Valenz 1982 21 37 285.0 31.2 116.1
Mike Nagy 1969 21 28 196.7 31.1 115.4
Denny McLain 1965 21 29 220.3 30.4 114.9
Larry Dierker 1968 21 32 233.7 30.7 114.8
Ray Sadecki 1961 20 31 222.7 30.6 113.8
Bert Blyleven 1972 21 38 287.3 30.5 113.6
Greg Maddux 1988 22 34 249.0 30.8 113.0
Catfish Hunter 1967 21 35 259.7 30.1 113.0
Jerry Garvin 1977 21 34 244.7 30.8 112.6
Dean Chance 1963 22 35 248.0 30.2 112.6
Dave Rozema 1977 20 28 218.3 31.8 112.5
Dave Boswell 1967 22 32 222.7 28.8 112.1
Floyd Youmans 1986 22 32 219.0 28.3 110.9
Ismael Valdes 1995 21 27 197.7 29.8 110.8
Britt Burns 1980 21 32 238.0 30.3 110.6
John Smoltz 1989 22 29 208.0 29.2 110.5
Bert Blyleven 1971 20 38 278.3 29.6 110.0
Bill Butler 1969 22 29 193.7 28.8 109.9
Burt Hooton 1972 22 31 218.3 29.5 109.6
Ramon Martinez 1990 22 33 234.3 28.8 109.6
Roger Erickson 1978 21 37 265.7 30.3 109.5
Jim Palmer 1966 20 30 208.3 28.9 109.4
Kerry Wood 1998 21 26 166.7 26.9 109.4
Joe Coleman 1969 22 36 247.7 28.9 109.1
Ed Correa 1986 20 32 202.3 27.7 108.9
Ray Culp 1963 21 30 203.3 28.0 108.7
Mark Lemongello 1977 21 30 214.7 30.3 108.1
Carlos Zambrano 2003 22 32 214.0 28.3 107.9
Denny McLain 1966 22 38 264.3 28.4 107.4
Steve Dunning 1971 22 29 184.0 28.0 107.4
Gary Nolan 1970 22 37 250.7 28.4 106.9
Don Robinson 1978 21 32 228.3 29.3 106.9
Clay Kirby 1970 22 34 214.7 27.9 106.7
Wayne Simpson 1970 21 26 176.0 28.1 106.4
Dave Rozema 1978 21 28 209.3 30.3 106.2
Bret Saberhagen 1985 21 32 235.3 29.1 106.0
Catfish Hunter 1968 22 34 234.0 28.5 106.0
Dennis Eckersle 1976 21 30 199.3 27.4 106.0
Storm Davis 1983 21 29 200.3 28.7 105.9
Les Cain 1970 22 29 180.7 27.3 105.7

In these 50 seasons are 42 unique pitchers. It is telling that only four pitchers have made the list since 1990 which is possibly an indication that organizations are more careful and indeed are heeding the advice of Wright at least indirectly. Of course, the things that jumps out to me are the two recent additions to this list, Kerry Wood and Carlos Zambrano of the Cubs. Wood did incur a serious injury that wiped out the end of 1998 and all of 1999 and suffered a sore tricep this season. Zambrano has yet to be injured but his precense on the list and his continually high pitch counts make me a little uneasy. (As an aside it should be noted that the pitch count estimator estimated 107.9 pitches per start for Zambrano in 2003 when he actually had 106.4).

To test point (4) I ran a query of those pitchers aged 23 or 24 who threw more than 115 pitches per start in 25 starts or more. This produced a list of 36 seasons with 30 unique pitchers.

Name            Year   Age         GS     IP           BFS     P/GS 

--------------- ------ ----------- ------ ------------ ------- -------
Rick Sutcliffe 1979 23 30 242.0 33.9 124.7
Jim Bouton 1963 24 30 249.3 33.5 124.2
Fernando Valenz 1984 23 34 261.0 31.7 122.1
Jim Hughes 1975 23 34 249.7 32.4 120.7
Dick Drago 1969 24 26 200.7 32.6 119.4
Bert Blyleven 1975 24 35 275.7 31.5 119.4
Joe Coleman 1970 23 29 218.7 31.7 119.2
Jack Hamilton 1962 23 26 182.0 31.5 119.0
Denny Lemaster 1963 24 31 237.0 31.5 119.0
Jim Maloney 1963 23 33 250.3 30.6 118.9
Tommy Greene 1991 24 27 207.7 31.7 118.7
Lynn McGlothen 1974 24 31 237.3 31.9 118.4
Jim Merritt 1967 23 28 227.7 32.5 118.4
Livan Hernandez 1998 23 33 234.3 31.5 118.3
Jon Matlack 1974 24 34 265.3 31.6 118.0
Frank Tanana 1977 23 31 241.3 31.4 117.8
Fernando Valenz 1983 22 35 257.0 31.3 117.5
Mel Stottlemyre 1965 23 37 291.0 32.1 117.5
Clay Kirby 1971 23 36 267.3 30.8 117.4
Don Sutton 1968 23 27 207.7 31.4 117.3
Denny McLain 1968 24 41 336.0 31.4 117.3
Dean Chance 1964 23 35 278.3 31.2 117.3
Bert Blyleven 1974 23 37 281.0 31.1 117.2
Dennis Eckersle 1978 23 35 268.3 32.0 117.1
Andy Messersmit 1969 23 33 250.0 30.5 117.1
Jim Kaat 1962 23 35 269.0 31.8 117.0
Joe Coleman 1971 24 38 286.0 30.9 116.8
Larry Dierker 1970 23 36 269.7 31.4 116.7
Dave Righetti 1982 23 27 183.0 29.8 116.1
Steve Barber 1961 23 34 248.3 30.6 116.0
Bret Saberhagen 1987 23 33 257.0 31.8 115.7
Chuck Estrada 1961 23 31 212.0 29.8 115.5
Dick Ellsworth 1963 23 37 290.7 31.4 115.4
Stan Bahnsen 1968 23 34 267.3 31.5 115.4
Sam McDowell 1966 23 28 194.3 28.8 115.1
Blue Moon Odom 1968 23 31 231.3 30.6 115.0

Once again very recent pitchers don't really show up on the list with the exception of Livan Hernandez in 1998.

In looking at these lists it is apparent that something has changed in the workloads of young pitchers since the late 60s and 70s. I believe there are three primary reasons:


  • The focus on pitch counts is the most obvious explanation. Organizations seem to be protecting their young pitchers better by not working them so hard when they first reach the majors. A case in point is Royals rookie Zack Grienke. In 14 starts Grienke has yet to throw more than 109 pitches or pitch more than 7 innings. I believe the Royals are doing the right thing with Grienke because they are not allowing him to pitch when he is tired. It's clear from watching his starts that he tires around 90 pitches and so is likely more prone to injury as his mechanics degrade past the point of fatigue.




  • A secondary explanation is the use not only of closers which came into vogue in the late 1970s but the addition of "setup men" in the 1990s. A starter on a team with a solid bullpen rarely needs to go more than 7 innings these days which puts downward pressure on their pitch counts down. These two factors together are easily demonstrated by looking at the number of compete games in the major leagues that has gone from 20% in 1980 to just 4% in 2003.




  • A third factor is the increased run environment that pitchers have toiled in since 1993. More runs means managers taking pitchers out of games sooner thereby limiting innings and pitch counts.


  • These last two points are illustrated by the fact that if you look at the top 100 seasons since 1960 ranking them in descending order by IP per start you won't find any seasons after 1989. In fact, it isn't until 147th place that Roger Clemens' 1997 season appears when he averaged 7.8 innings in 34 starts.

    But the real question is whether this altered pattern has actually decreased the number of injuries to starting pitchers. Jazayerli and Woolner suggest that the jury is still out but are hopeful in their rebuttal stating that "A revolution in the management of starting pitchers is underway, and the early signs suggest that the revolution may well lead to fewer injuries." They don't, however, list what these signs are. This question is also difficult to analyze since teams use the disabled list more frequently today than in the past in part because diagnostic technology has improved and therefore precautionary DL stints are more common, and partly because of the large investment that players represent that encourages a better-safe-than-sorry approach.

    I think all parties agree that its clear that abuse along the lines documented by Wright indicates that young pitchers can and were overworked fairly routinely in the past which often led to serious injuries. However, if evidence of reduced injuries to young starters in the present era fails to materialize, it could well be that James is correct in surmising that most injuries to pitchers both young and old are catastrophic and not the result of overuse. The truth probably lies in the middle somewhere - young pitchers are prone to both overuse and catastrophic injuries while mature pitchers typically incur catastrophic injuries. Understanding the relative frequency of each is the key to formulating studies and systems that might detect it.

    A second explanation as to why recent pitchers don't show up on these lists assuming that injury frequency has not lessened, might be the alteration in workload from a very young age. Since young pitchers have been so closely monitored throughout their careers from little league on up, their arms are not as strong as pitchers of the past. In that case the prevelance of arm injuries might not change but would simply be triggered at lower and lower pitch counts. For example, in the 1970s a game of 140 pitches might be considered the borderline for a mature starter whereas today it might be 120 pitches and tomorrow 100 pitches.

    Four Man Rotation
    And finally, this leads us to the title of this post. Could a return to the four man rotation actually help the situation? Wright found in his study that pitchers are not less effective on three days rest than on four when looking at data from 1986-87 and advocated a return to the four-man rotation. This was backed up by a study done by Jazayerli using data from 1978 to 1995. Of course, far fewer pitchers ever pitch on three days rest today. The last manager to be a strong proponent was Earl Weaver in the early 1980s and the last experiment with it I can remember is the Reds Bob Boone's in 2003 which ended by mid season despite support from pitching coach Don Gullet and assistant GM Brad Kullman.

    It seems to me (and others I've read) that the focus on reducing pitch counts has become married to the assumption that more rest between starts is also good for young pitchers. You could easily see where this might be the case since both reduce the number of pitches a pitcher throws over the course of a seaon. But is it just possible that for most pitchers throwing fewer pitches (meaning a maximum of 105 for young pitchers and 120 or so for mature pitchers for example) more frequently (every four days instead of five) will actually build arm strength, endurance, and lead to fewer injuries in the long run? Of course it will also have the side benefit of allowing better pitchers to throw more innings thereby producing more wins for the team that employs the four-man rotation. I'd love to see some team try it in 2005 but now that the pendulum has swung in the opposite direction it will likely take a while for it to swing back.



    Other reading on pitch counts:
    Kicking the crutches out
    What Pitch Counts Hath Wrought
    What Pitch Counts Hath Wrought: Part Deux
    Swinging from the Heels: Painting a Fake Tunnel on a Blind Alley

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