Wow, this is great stuff.
This is why I miss Bill James yearly abstracts he used to write.
BTW, what ever happened to him?
Last I heard, he had been hired by the Red Sox as a consultant (this was a couple of years ago, don’t know if he still works for them). Hmmm, who won the World Series last year?
mhendo, this is good stuff! I’ve got one for you that’s been gnawing at me for a couple of years now.
About two years ago I attended a Baseball Prospectus “pizza feed” here in Boston. Joe Sheehan made the claim that home field advantage is almost entirely a tactical effect – knowing you bat last, basically.
I always figured that could be tested, by looking at win-loss records for games decided by wide margins – say, by 5 runs or more. If Mr. Sheehan’s premise is correct, home field advantage should be minimal in lopsided games.
So…
What percentage of all games are won by the home team?
and
What percentage of all games decided by 5 or more runs, are won by the home team?
Thanks!
-P
Sorry for the delay in responding. I’m actually out of town right now, visiting Boston, and i won’t be back home until Monday. My computer is a desktop, and is still at home, so i won’t be able to look at the database until Monday.
If the data were set up in a different way, i think that Trunk’s question would probably be pretty easy to answer, but the way it is right now i’m not sure that it’s possible to extract that data from the table. I’ll think about how it might be done, and see if i can make it work.
Parthol’s question is perfect for the type of data this table contains, and will be very easy to answer.
I’ll report back on Monday evening, after i get home.
Well, i’m back from Boston.
I still can’t work out how to answer Trunk’s question, but i’m going to keep working on it.
As for Parthol’s question:
There have been 184,147 games played since 1871. Of these, the home team has won 100,026 (54.3%). And of these 100,026 victories, 26,694 (26.7%) have been by five runs or more.
Since 1970, there has been a total of 73,879 games. The home team has won 39,726 (53.8%), and 9,674 (24.4%) of these home victories have been by five runs or more.
In total, there have been 49,564 games decided by five or more runs. Of these, the home team won 22,870 (53.9%). Since 1970, there have been 18,747 games decided by five runs or more, with the home team winning 9,674 (51.6%).
So, it seems that the home team advantage for winning five-run games is really not that much different from the home team advantage in winning all games. As a whole, it seems that the home team enjoys a slight advantage, whether in close games or in blow-outs.
Starting in 1946 (the first year after WW2, when teams were back to full strength) and going up to present day, I was wondering if you could answer the following questions, mhendo:
-
What’s the winning percentage for all teams who successfully stole three or more bases in one game?
-
What’s the winning percentage for all teams who were caught stealing three or more times in one game?
I predict the winning percentage for successful stealing teams - in terms of absolute distance from .500, in either direction - will be closer to average than the winning percentage of teams who got caught stealing.
In other words, getting caught stealing repeatedly is worse than swiping a bunch of bases.
Thanks!
First, i can only do this from 1960 onwards; the years before don’t contain stats for stolen bases and caught stealing.
The first thing i did in order to answer this question was to eliminate all games where BOTH teams stole three or more bases. That eliminated 247 games.
Now, there was a total of 8,748 games where one team stole three or more bases and the other team stole fewer than three bases. In those games, the team that stole three or more bases won on 5,981 occasions, for a winning percentage of .684.
Again, i eliminated games where both teams were caught stealing three or more times. This time, that only involved getting rid of 5 games.
Then, looking at games where one team was caught stealing three or more times, and the other team was caught stealing fewer than three times, i found a total of 788 games. In those games, the team that had three or more men caught stealing won on 512 occasions, for a winning percentage of .650.
Just a little lower than the winning percentage for the “three stolen bases” statistic.
My theory about this is that, whether you steal bases or are caught stealing, you still have to have men on base for this to happen. So, teams with high stolen base numbers or high caught stealing numbers are also teams that get plenty of runners on the bases, and so are more likely to score runs.
I’m not sure that the stats bear out your hypothesis!
Begging to differ–with respect to the period since 1970, your results appear to show a dramatic difference in home winning percentage in blowouts (.516) versus close games (.545). When dealing with a sample size that large, this is a very significant difference. It would appear that about two-thirds of the home advantage disappears in blowouts, and could plausibly be attributed to the strategic advantage of batting last.
Granted, the disparity fades when one includes the earlier (1871-1970) period. One can conjecture any number of reasons why this might be the case. Travel conditions were more difficult in the earlier era, parks had more unique configurations, fields were more poorly maintained (with greater advantage for the home team in knowing the local configuration), and fans were rowdier and closer to the field. Perhaps these made for a more universal home advantage. As travel has eased, security has improved, and parks and playing conditions have standardized, perhaps other sources of home advantage have faded away, leaving mostly the strategic advantage of batting last and knowing how many runs you need in a close game.
Fair enough.
I’ll concede to someone who, undoubtedly, has a better knowledge of statistics and significant differences than i do. I made the mistake of comparing assuming that a couple of percentage points wasn’t very significant. I stand corrected.
mhendo, thanks much for running the numbers on my question. If you have time, could you break it down a bit further? Specifically, considering only games from 1970 onward, could you calculate:
% of all 1-run games won by the home team?
% of all 2-run games won by the home team?
% of all 3-run games won by the home team?
% of all 4-run games won by the home team?
% of all 5+ run games won by the home team? (already figured, as 51.6%)
I’d be interested in seeing if there’s a more-or-less linear trend.
Much obliged,
-P
Here ya go. V = visiting team, H = home team.
Since 1970
One-run games (V) 8,673
One-run games (H) 13,439
Home victories 0.608
Two-run games (V) 6,854
Two-run games (H) 6,914
Home victories 0.502
Three-run games (V) 5,540
Three-run games (H) 5,480
Home victories 0.497
Four-run games (V) 4,067
Four-run games (H) 4,219
Home victories 0.509
5+ run games (V) 9,073
5+ run games (H) 9,674
Home victories 0.516
Seems that home field advantage is a BIG deal in very close games.
Well, that’s fascinating. I never would have predicted that pattern in a million years.
I suppose it makes sense, though. Home advantage benefits the home team, but it also tends to hold down the margin of victory, because the home team (a) doesn’t bat in the bottom of the ninth when it’s ahead; and (b) has its last at-bat truncated in walk-off victories.
Maybe there’s a better way to answer Parthol’s question. It’s in extra-inning games that the advantage of batting last most comes into play. What are the percentages in extra-inning games? (If possible games which are tied after eight innings can be added to the mix, because a tie game in the ninth is strategically identical to an extra-inning game.)