1988 NLCS Game 4: Unlikely HR by Scioscia off Gooden

It was played on this date in 1988. In the 9th inning, Mike Scioscia hit a 2 run HR off Dwight Gooden to tie the score. The Dodgers won in extra innings to tie the series at 2-2 (some guy named Gibson hit a HR).

Gooden allowed 10 HRs that year while facing 1024 batters. Taking out 4 IBBs, his HR rate is 10/1020 = 0.0098 or 0.98%

Scioscia hit 3 HRs that year in 452 PAs. Taking out 12 IBBs, his HR rate is 3/440 = 0.0068 of 0.68%.

I recall thinking at the time that this had to be fairly unlikely, that Scioscia would hit a HR off of Gooden. It does not seem that platoon splits played much of a role here. I wonder how many times a HR was hit in a post season game when both the pitcher and the hitter had a HR% under 1.

Gooden threw 133 pitches in that game. That could have been a factor. But Gooden had a high that year of 138 pitches in a game (and did not give up a HR in that game).

He did not give up a HR in any of his top 5 pitch count games that year and those all had at least 126

He had 22 starts with 100+ pitches but gave up a total of only 5 HRs in those games.

I just started looking at World Series HRs in the deadball era and it seems like alot of them were like this, both pitcher and hitter below 1%. But, that was probably true for almost all World Series PAs during this time. So given that there were 6839 World Series PAs from 1903-1919, alot of the HRs would fit this criteria. And some were inside the park.

It looks like the HR% in all of MLB (just AL/NL) from 1903-1919 in regular season games was 0.39%. In World Series games it was just a bit higher at 0.42% But even if it was the same in the WS, we would have to expect that alot of them would be with both pitcher and hitter below 1%. 

I will probably have to start my search at 1920. But off the top of my head I don't know of an easy way to check. And Tom Niedenfuer was over 1% in 1985 even if Ozzie Smith was below (but just barely).

 

So I hope to get into this question in a future post. 

Update 10-10-2024: 

 

I used Bill James's Log5 formula to calculate the expected HR% in a Scioscia-Gooden match up. It uses the % for the pitcher and batter as well as the league average. I came up 0.376% or .00376 HRs each time they faced each other. That is 1 every 266 times.

My guess is that alot of those dead ball era world series HRs will be lower just because HRs were so rare then. But again, they had a large number of low probability opportunities, so some would happen

If anyone has any suggestions for least likely post season HRs since 1920, let me know. For World Series games I am not sure what to use for the league average. Maybe an average of the 2 leagues.

 

I calculated the % for the HR Jimmy Sebring hit off of Cy Young in the 1903 World Series (the first one) and came up with 0.83% (I used the MLB average for league average). It might be surprising that this is higher than the Scioscia-Gooden case. But both Gooden and Scioscia were below their league average while Sebring and Young were both above it.

 

That Log5 formula is

where P_B is the hitter’s HR%, P_P is the HR% allowed by the pitcher and P_L is the league HR%. P_B,P is the probability (or %) that the player will hit a HR against the pitcher.