At Hall Watch, evaluating quality is Job 1. For starting pitchers, it is not easy. There are so many choices. You can start with the components- walks, home runs, strikeouts, ground balls, fly balls and line drives, and work from there. You can start with the runs allowed and work from there. Or you can look at the won-loss record and work from there. You might very well use a different method for career evaluation than you would use for seasonal evaluation.
In Part 1 of this series, starter standards 1905-2005 were calculated. In Part 2, we looked at quantity measures for starters throughout the ages. Now, it's quality time.
The Components of Runs Allowed
For batters, we look first and foremost at the components of run production-on base percentage and slugging percentage, rather than runs scored or driven in. Why is that? For any specific batter, the number of runs that he scores or drives in will be dependent to a great extent on the performance of the hitters around him in the lineup. We could try to adjust runs scored or driven in to reflect batting order context, but nobody does, because it's just too difficult, even though for Rickey Henderson or Tim Raines, say, it might provide very meaningful information. On the other hand, measuring the components for a particular batter is easy as pie, is totally independent of the performance of other batters in the lineup and provides the information that we need to evaluate quality. It is not quite the same for pitchers.
Walks, Home Runs allowed, and strikeouts are components of runs allowed and are special because they are independent of team defence. They are, aren't they? Well, no. I am not speaking of inside-the-park homers either, but rather the important contribution that catchers make through pitch selection and through the fine art of framing. Still, the quality of the pitcher is the most important factor in these components. What are the other components of runs allowed?
The other components are:
1) opposition batting average on balls in play (BABIP), more commonly called, from a pitcher's perspective, defensive efficiency ratio (DER)
2) stolen base/caught stealing, wild pitch/passed ball/balk, double plays per opportunity and runner advancement ratio (first to third on singles, scoring from first on doubles...)
3) errors
4) situational performance differences, and,
5) bullpen support (ratio of bequeathed runners who score).
Defensive Efficiency Ratio for a Pitcher
It is well known that both pitchers and team defence contribute to the pitcher's DER, but over a season a pitcher's DER is mostly independent of the pitcher's performance. Rather luck or defence plays a greater role over this time frame. Over a number of seasons though, how important is luck vs. the quality of the pitcher in the number of hits the opponents get on balls in play. I did a small cohort study using the delta H statistic provided by Baseball Prospectus. Delta H compares the number of hits on balls in play surrendered by a pitcher with the similar ratio for the team. A negative delta H is good and signifies that the pitcher has given up fewer hits than would be expected from the team defence. At the same time, I thought that it would be useful to look at the Delta R statistic to gauge the importance of the factors other than opposition BABIP in runs scored against a pitcher.
I wanted to find out about power pitchers and the impact of handedness, so I started with five well-known power pitchers from different eras- Walter Johnson, Lefty Grove, Bob Feller, Sandy Koufax and Tom Seaver. For their cohorts, I choose pitchers on their clubs of opposite hand, who pitched the most innings over a period of years. The cohorts were Joe Boehling (1912-1916) and Tom Zachary(1919-1925) for Walter Johnson, George Earnshaw(1928-1933) for Lefty Grove, Al Milnar (1938-1941) for Bob Feller, Don Drysdale (1956-1966) for Sandy Koufax and Jerry Koosman (1967-1977) for Tom Seaver.
Before comparing the pitchers and their cohorts during the specific seasons, here are their career dH and dR statistics:
Pitcher dH dR Walter Johnson -320 -62 Joe Boehling 42 -46 Tom Zachary 93 -146 Lefty Grove -44 -137 George Earnshaw -3 -8 Bob Feller -52 -56 Al Milnar 21 6 Sandy Koufax -94 6 Don Drysdale -12 -48 Tom Seaver -199 -34 Jerry Koosman 61 -32At first glance, the power pitcher seems to have a marked advantage in preventing hits on balls in play. Let's compare the power pitchers and their teammate cohorts during the seasons under review:
Pitcher Seasons IP H dH R dR Johnson 1912-16 1793 1326 -106 421 -53 Boehling 1912-16 805 732 30 329 -40 Johnson 1919-25 1746 1631 -91 682 -21 Zachary 1919-25 1383 1576 21 677 -54 Grove 1928-33 1683 1577 -9 596 -78 Earnshaw 1928-33 1353 1345 -5 723 -1 Feller 1938-41 1237 981 -61 472 -38 Milnar 1938-41 749 780 5 392 -8 Koufax 1956-66 2282 1722 -93 791 10 Drysdale 1956-66 2848 2543 -8 1089 -29 Seaver 1967-77 2814 2230 -65 849 -56 Koosman 1967-77 2310 2060 17 884 -28
https://www.battersbox.ca/article.php?story=20051228213447810