Forbes Field, Hitter’s Nightmare?

This article was written by Ron Selter

This article was published in 2002 Baseball Research Journal

Forbes Field was one of the very first classic era ballparks (only Philadelphia’s Shibe Park preced­ed it) to be built in America. It was the home of the Pittsburgh Pirates for 62 seasons after it opened June 30, 1909. Forbes Field has been regarded as a spacious park and a poor park for hitters. Only in the 1947-53 seasons when the “Greenberg Gardens” reduced the left-field foul line distance by 30 feet, was the park considered friendly to hitters.

The conventional wisdom about Forbes Field is illustrated by the following quotations taken from var­ious ballpark books:
“No no-hitter was ever pitched here. Given the fact that the Pirates, Grays, and Craws played here for 62 years, that is an incredible statistic,” wrote Philip Lowry in Green Cathedrals.

“It was one of the most spacious parks in baseball, so much so that when slugger Hank Greenberg’s con­tract was sold to Pittsburgh in 1947, he refused to report unless the team moved the fences in” and “… the park remained a nightmare for many hitters including the great Roberto Clemente,” Eric Enders wrote in Ballparks: Then And Now.

“Strangely a no-hitter was never pitched in the entire history of Forbes Field,” Larry Ritter wrote in his Lost Ballparks.

Much of this conventional wisdom reflects two facts: (1) Forbes Field was spacious, more so than the average NL park in the time period 1909-46, and (2) during this period the park was not conducive to the hitting of home runs. How spacious was Forbes Field relative to the other NL parks? When it opened in June 1909, only Redland Field in Cincinnati was larg­er. In the ensuing years, parks in other NL cities var­ied in size, but Forbes Field’s overall size changed very little and was never less than 457 to center field. A comparison of the average outfield distances for Forbes Field and the entire National League is shown in the following table.


Table 1. PARK SIZE 1910-46

Year Forbes Field NL Average
1910 395 380
1920 395 382
1925 388 383
1930 390 374
1935 390 373
1940 390 375
1946 390 373


The second item which leads to Forbes Field’s reputa­tion as a poor park for hitters was the undisputed evi­dence of relatively few home runs being hit at Forbes Field.The concept of a park Home Run Factor has been developed to measure the number of home runs at a given park relative to the league average for that season. The determination of the park Home Run Factor adjusts for the home team’s hitters’ and pitch­ers’ proclivities for hitting and giving up home runs. By definition, the league average Home Run Factor is equal to 100.The following table shows the Home Run Factors for Forbes Field:



Years Forbes Field
1920-29 57
1930-39 62
1940-46 68
1909-46 (avg) 62


Compared to the average NL park, Forbes Field was about 40% below average in home runs. By contrast, Forbes Field was always regarded as a good park for triples. How much above the average NL park has not been known. Indirect evidence supporting the view of Forbes Field as a good triples park includes: (1) Owen Wilson of the 1912 Pirates set the major league single­ season record for triples (36) while playing half his games in Forbes Field, and (2) in 18 seasons (1921-37) the Pirates led the NL in triples 14 times.

Except for the Home Run Factors, all of the above evidence consists of data that is either indirect or merely suggestive. Recent research into NL Home/Road batting by park has made available some direct evidence that bears on the question: Was Forbes Field a poor park for hitters?


For the last three years of the Deadball Era (1917-19), Park Factors were computed for six bat­ting categories based on the batting data for the Pirates and their opponents in games at Forbes Field vs. data for Pirates games in all other NL parks. The resulting Park Factors are as follows:



Category Park Factor NL Rank
BA 102 3
OBP 100 4
SLG 104 2
2B 95 4
3B 157 1
HR 56 8

*All categories are rate data; (e.g., 2B are 2B per AB)


Note that despite being dead last in home runs, Forbes Field was the second (behind Philadelphia’s Baker Bowl) best park for slugging. This result is due to the marked superiority of Forbes Field for triples — 50% better than the average NL park. In general, in the deadball era triples had a greater impact on offense than home runs. For the three deadball seasons studied, the NL seasonal average was 67 triples per team, nearly three times the average per team for home runs (23).


For the nine-year time period 1928- 1936 Park Factors were computed for six batting cate­gories based on the batting data for the Pirates and their opponents in games at Forbes Field vs. batting data for the Pirates games in all other NL parks. The resulting Park Factors are as follows:



Category Park Factor NL Rank
BA 104 2
OBP 102 2
SLG 101 3
2B 94 5
3B 161 1
HR 62 7

*All categories are rate data; (e.g., 2B are 2B per AB)


In this era of the lively ball Forbes Field ranked sec­ond in batting average, on-base percentage, and again first in triples. Ranking first in triples was no surprise. What was more interesting is how a spacious park like Forbes Field ranked second in batting average, and on-base percentage. Had other NL parks been modi­fied to make them larger, and thus Forbes Field became relatively smaller? The answer is no. The trend in the other NL parks in the 1920s and 1930s involved closer fences and smaller dimensions. In par­ticular, Braves Field in 1928 was greatly reduced in size, and Redland Field in Cincinnati was downsized in 1927 by moving home plate 20 feet toward center field. In fact, despite Forbes Field being slightly small­ er after 1925 (when right field was reduced by the extension of the grandstand), the relative size of Forbes Field actually increased from the deadball era to the 1930s. Based on the data shown above in Table 1, Forbes Field was 3.4% larger than the NL average park in 1920; by 1930-35 it was 4.4% larger than the NL average.


Between 1925 and 1947 Forbes Field was a clearly asymmetrical park as the left field distance was 365 while right field was 300 ft. However, overall the aver­age right field distance was only 3% less than the aver­age left field distance. Did this 3% difference provide an advantage to left-handed batters? Pittsburgh team batting data for left-handed (LH) and right-handed (RH) batters are now available for 1927-37 and 1940-42. A comparison was made between the home and road batting data for both LH and RH batters.6 A sample (the 1929 season) of the data is shown:



Home .334 .417 .511
Road .329 .399 .486
H/R ratio 1.017 1.044 1.051


Home .311 .360 .430
Road .265 .323 .359
H/R ratio 1.175 1.116 1.199


One inherent problem in comparing LH and RH bat­ters’ performances is that LH batters are generally better hitters — LH batters hit better than RH batters at home and on the road. The H/R ratio for LH and for RH was used to measure how LH and RH batters performed relative to their performance at other NL parks. The comparison for the years 1927-37 and 1940-42 was based on the three categories of batting average, on-base percentage and slugging percentage and is shown below:



Category LH H/R Ratio RH H/R Ratio
BA 1.074 1.102
OBP 1.06 1.088
SLG 1.078 1.108


The above data clearly show that LH batters had no advantage at Forbes Field — relative to other NL parks in any of the three offensive categories. The average H/R ratio differential (RH-LH) was 2.9 points. However, there is a catch. The average NL ballpark in this time period favored LH batters. Available data show the average NL park (1928-36) had a RF average distance some 7% less than the average LF distance. Thus RH Pittsburgh batters could be expected to have a larger disadvantage in road games than at home. As a result, the RH batters should hit relatively better (measured by the H/R ratio) at home when compared to LH.

The data conforms to this expectation — the differential between RH and LH batters (2.9 points of H/R ratio) is about the same as the relative LF/RF average distance relationship between the average NL ballpark and Forbes Field (107% to 103%). The con­clusion is that Forbes Field slightly favored LH bat­ters, but to a lesser degree than the average NL park in this time period.

RON SELTER is an economist who lives in El Segundo, CA. A member of SABR since 1989, he has done research on the minor leagues and on ballparks.



Lowry, Philip J. Green Cathedrals, rev ed. Reading MA; Addison-Wesley, 1986: 218.

Enders, Eric. Ballparks Then And Now. San Diego, CA: Thunder Bay Press, 2002: 128.

Ritter, Lawrence S. Lost Ballparks. New York, NY: Penguin, 1992: 65.

Total Baseball 4th ed. Thorn, John and Pete Palmer, eds. New York, NY: Penguin, 1995: 2,245-46.