So I guess I'll just do these as a rambling series of posts alphabetical by city name, for as many cities as I have time for in a given post.
BALTIMORE
Oriole Park I: 0% (1884)
Oriole Park II: 0% (1890)
Oriole Park III: 20% (1893), 18% (1895), 33% (1899)
These were three different parks all built within blocks of each other, not a ballpark rebuilt twice on the same site. I can't really find anything about the first couple, and 1890 was the only full season that Oriole Park II was even open. According to the scant information on
Seamheads the dimensions we know of for Oriole Park III did not change in its eight years of operation - 1899 had a particularly small sample size so an overall rate in the low 20s might be the best place to set it.
Memorial Stadium: 0% (1958), 0% (1966), 0% (1979)
Did not find any ITPHRs here in the years I ran. It was
deeper to dead center in its first few seasons, but not remarkably deep by 1950s standards. Probably an average rate would do for this one.
BOSTON
South End Grounds I: was below average for all the 1870s-80s seasons I ran. Rate of about 7% would do it.
South End Grounds II: 6% (1890), 0% (1893)
Center field sure looks huge in that 1893 photo on Wikipedia, and lots of home runs were hit here, just not the inside-the-park kind according to the data on hand. It was short down both lines like the Polo Grounds.
South End Grounds III: 1% (1895), 1% (1899), 5% (1900), 3% (1901), 4% (1902), 0% (1903), 0% (1905), 15% (1907), 0% (1908), 4% (1910), 4% (1913)
So yeah, this park was always well below average for ITPHRs. 3 or 4% would fit for many years.
Huntington Avenue Baseball Grounds: 100% (1901), 85% (1902), 100% (1903), 83% (1905), 72% (1907), 82% (1908), 40% (1910)
A big yard that was excellent for inside-the-park homers in the 1900s. I guess the drop in 1910 must have been because the left field line was shortened from 350 feet down to 305 when the third-base bleachers were extended,
according to Seamheads.
Fenway Park: 100% (1913), 33% and 40% (1915), 29% (1917), 23% (1919), 6% (1920), 16% (1921), 12% (1923), 3% (1925), 0% from 1931 forward
Few home runs of
any kind seem to have been hit in Fenway in the 1910s, so the numbers are a bit swingy there. It ran about average in the early '20s and then I have no more ITPHRs recorded for the seasons I did, not even in 1931 when it was 468 to center. I would think the only way to ever get one at Fenway in its current configuration would be to hit the ball into that notch just right of center, wouldn't everyone say?
Braves Field: 67% (1915 partial season), 94% (1917), 95% (1919), 94% (1920), 89% (1921), 97% (1923), 93% (1925), 0 and 3% (1921), 0% (1938), 1% (1948)
This was very well known as a great park for ITPHRs (turns out the Braves owner deliberately designed it to be that way). The rate is remarkably consistent in the 90-95% range until the fences were brought way, way in before the 1928 season and it looks like it was probably just average from then on.