Here is the long form of Bill James analysis
http://207.56.97.150/articles/james_onerun.htm
A few excerpts
Are there any identifiable characteristics of teams that win their one-run games, as opposed to those that lose their one-run games?
As long as you don't make a big deal out of it, yes. Teams which do well in one-run games have more or less all of the characteristics you would expect them to have, but only to a small extent.
My method here was to take all teams since 1950, and identify the top 50 and the bottom 50 teams by how they performed in one-run games, relative to expectations. I broke it off at 1950, because I didn't want to get back into the bad-data era. I then figured the average team stats for each group of 50 teams, and compared the two groups.
The 50 teams which did well in one-run games had more stolen bases (96-92 on average), more sacrifice bunts (71-67), more complete games (35-31), more saves (34-30), issued fewer walks (513-531), drew more walks (526-520) and had a better ERA (3.77 to 3.91).
The 50 teams which did poorly in one-run games hit more home runs (127-117), scored more runs (674-658), had a higher slugging percentage (.386-.380), a lower on-base percentage (.325-.323), used more relief pitchers (278-257), threw more wild pitches (47-44) and had more balks (8-7). They were more likely to play in hitter's parks (park factors 100.3 vs. 98.5).
I think that, generally, one would expect all of these things to be true -- one-run teams play one-run ball and have strong pitching. However, the degree to which these things are true is extremely minor. If you tried to project it backwards -- that is, take a team's characteristics and predict whether or not they would do well in one-run games -- you'd get nowhere, because the tendencies just aren't strong enough to work in that way.
Winning One-Run Games a Valid Team Trait, or Just Something That Happens Sometimes?
What we really want to know here is whether winning one-run games is a persistent trait-meaning that the same teams and same managers do it every year-or a transient outcome, meaning that it's probably just luck.
Ruane concluded that "how a team does one year in close games is absolutely no use in predicting how it will do the next," and also cites a study in the 1997 Baseball Research Journal by Bob Boynton, in which Boynton had apparently reached the same conclusion, although I haven't seen that article.
My conclusion is slightly different. My conclusion is that winning a lot of one-run games has a persistence of zero (meaning that it appears to be luck) but that losing a lot of one-run games is not necessarily completely meaningless. It's mostly just bad luck, but it doesn't appear to me that it entirely disappears in the following season.
Here's what I did. First, I established the expected winning percentage in one-run games for every team in my data base, and then applied that to the number of one-run games that each team played. By so doing, I identified all of the teams which were five games better or five games worse than expected in one-run games.
There were 140 teams which exceeded their expected one-run winning percentages by five games or more. These 140 teams, in the aggregate, were +897.7 wins.
In the following seasons, however, these teams were -23.6. In other words, they had, as a group, no tendency whatsoever to be better than average in one-run games, in the following season. The trait has a persistency of zero.
But there were 153 teams in my study which did 5.0 or more games WORSE than expected. In the aggregate, these teams were negative 990.6 wins. In the following seasons, they were also negative 93.9 wins.
In common language, my study suggests that you can't win more than your share of one-run games consistently, but you can lose more than your share, perhaps. It's not a HIGH rate of persistence -- 9% -- and it COULD be just a hiccup in the data. It's a pretty healthy hiccup -- 94 Wins is a pretty fair discrepancy in the data to be written off as luck.
Why did I reach a different conclusion from Ruane and Boynton? Well, first, my method is significantly different.
Ruane identifies the "best" one-run team of all time as the 1974 San Diego Padres, who went 60-102 overall, but an astonishing 31-16 in one-run games (29-86 otherwise), and the second-best one-run team of all time as the 1955 Kansas City A's (63-91 overall, 30-15 in one-run games.)
My study lists the same two teams one and two on the over-achievers list -- but then departs. His list of the five worst one-run teams and my list of the same are completely different, involving none of the same teams, and the rest of his top-five list and mine, after the top two, is also completely different. Using a different method -- I believe a better method -- I just reached a different result.
Second, I focused on extreme teams, the teams at the ends of the list, and ignored the middle of the chart. I'm not interested in how many teams may have gone +2 one year and -3 the next.
Studying the whole list, you could get such a large pile of chaff that you think you don't have any wheat at all. I think it is better to focus on the teams with strong tendencies in one season.
