One of the keys to the Yankees' early success has been their ability to win close games. So far, one third of the Yankees' victories have been decided by one run, which some might suggest indicates good fortune, while others see evidence of a team that knows how to win. There's no use trying to settle that chicken-and-egg debate, but we can examine the historical characteristics of teams that have thrived in nail biters.
If the Yankees continue to win 80% of one-run games, they'd not only set a franchise record but also surpass the all-time mark, which was established last season by the Baltimore Orioles (29-9; .763 winning percentage). In addition, it would also likely represent the greatest seasonal discrepancy between the Yankees' winning percentage in games decided by one run compared to all others, which is significant because the Bronx Bombers have never made the post season with anything approaching such a large divergence. In fact, in the 34 seasons when the Yankees won a higher percentage of one-run games than those settled by two or more runs, the team made the post season only five times (last occurring in 2005, when the difference was 5.6 percentage points, versus 23.3 currently), and almost half the time, they wound up finishing the regular season below .500.
Although the Yankees' past success has rarely been fueled by a special ability to win one-run games, most of the top performing teams in games decided by this narrow margin have done well in the regular season. Among the top-203 one-run game records in major league history, nearly 42% were turned in by teams with a full season winning percentage over .600, and 73% by those with a rate of at least .550. That seems encouraging, but there's a catch. Over 20% of the top one-one records in major league history came from teams that actually did better when the margin was two or more runs. If you remove these elite teams from the equation, 65% of the top one-run teams posted a full season winning percentage of .550 or better, and only 27% finished above .600.
Note: Represents full season records for teams with the top-203 winning percentages in one run games since 1901. Top chart is the entire population, while the bottom two charts are broken down based on the team's performance in one-run games versus all others.
It might be unsettling to some that the very best teams tend to perform relatively worse in one-run games, but that relationship should be intuitive. After all, if a team scores a lot of runs and doesn't give up many, their losses will tend to be close scores. And, sure enough, that's exactly what the data shows. Among the 42 top one-run record teams that actually did better in games decided by two runs or more, all but one was above average relative to their league in both scoring and preventing runs, and more than half were at least 10% better in both regards.
Note: Light blue shading indicates figures that represent at least 5% of the segment total.
Source: baseball-reference.com and proprietary
When considering only the teams whose one-record provided a boost to their overall season winning percentage, the distribution shifts toward the mean. Although there are still a few teams who significantly outperformed the league in terms of both run scoring and prevention, for the most part, clubs that over-achieved in one-run games had either below average hitting or pitching (but usually not both). These are the teams that either use good pitching to make up for a poor offense, or rely on a potent lineup to overcome weakness on the mound.
Note: Light blue shading indicates figures that represent at least 5% of the segment total. Dark blue shading indicates 2013 Yankees' current position on the matrix.
Source: baseball-reference.com and proprietary
Where do the 2013 Yankees fit into the profiles outlined above? After 40 games, the Yankees have scored only 95% as much as the average American League team, but they've allowed runs at only 87% of par. This puts them in a sweet spot for teams that have lofty one-run game records that exceed their overall winning percentages.
Based on the data above, it doesn't seem as if the Yankees' superior record in one-run games is the result of luck or winning know-how. Rather, the team's strong pitching and mediocre offense have provided the perfect combination for eking out close games. As the Yankees' roster evolves, some of the dynamics may change, but based on the status quo, it isn't unreasonable to expect the Bronx Bombers to continue winning more than their fair share of squeakers. That's not exactly how the Yankees have won in the past, but if the team ends the season in its typical perch atop the A.L. East, the end will have justified the means.