As the Cardinals have dominated the rest of the league — on Wednesday, they became the first 100-win team since the 2011 Phillies — many analysts have covered their phenomenal pitching staff. Even after we adjust for park and league factors, the team's performance makes history: Since the turn of the 19th century, just twelve other teams can top St. Louis's 76 ERA-. Ben Lindbergh wrote a superb piece at Grantland, explaining how most of that comes from cluster luck. In short, Cardinal pitchers have posted mediocre results with the bases empty, only to excel when runners reach; in general, pitchers don't control this sort of thing, so luck probably accounts for most of it.
Certainly, the Cardinals' pitching has been rather fortunate this season, to a greater extent than any other staff. But the luckiest unit of any kind resides a few states north, in Minneapolis. By a few different measures, the 2015 Twins offense has not only lucked out more than any other team this year — they, like the Cardinals, have had a season for the record books.
wRC tells us how many runs a player contributed to his team with his bat; BsR tells us how many runs he contributed with his baserunning. Add them up for all the club's players, and you'll get a theoretical measure of how many runs the team should have scored. I recognize that wRC does not capture every offensive outcome, such as ROE and doesn't separate infield singles from other singles, but it offers a pretty good barometer. Additionally, BsR is relative to average, so the true adjustment isn't perfect. This is a jumping off point and I recognize its imperfections. By this metric, however, these teams have overperformed the most:
The Twins lead the way — by a lot. According to BaseRuns, the Twins have won 10 more games than their output would suggest, and their offense has taken them there.
We don't see this level of overperformance that often. Since 1900, only 17 teams have topped their expected runs mark by 60 or more:
In other words, only eleven other offenses in recent history have been more fortunate than the 2015 Twins have been. (The legendary 2013 Cardinals sit several spots ahead of them.)
Others have noted the club's luck in the past: First came Jeff Sullivan in May, followed by a host of others in June. To the best of my knowledge, the last post on the topic went up in late July. Essentially, most pundits (like me!) thought that the Twins' first-half luck would disappear in the second half. That obviously hasn't come to pass, as the team has put together an entire weird season.
So how has Minnesota gone about doing this? Part of their overperformance comes from an element of the game that wRC doesn't measure: Only two other teams in the majors have reached base on errors more often than the Twins have. Still, though, taking advantage of a few miscues won't grant a team sixty runs. The answer here lies in the Twin's siutational statistics.
The Cardinals' pitchers have succeeded by improving their game with runners on base, a development which has received a lot of attention. The Twins' hitters haven't seen as much coverage, but they've done the same thing:
Granted, almost all teams will fare better when the pitcher has to work from the stretch — in 2015, the average bases-empty wOBA (.308) trails the average runners-on wOBA (.321) by thirteen points. The Twins have taken this to the next level, however, and what we know about offense makes that even more bizarre.
Offense in MLB isn't linear — i.e., teams that hit very well overall will score more runs than we'd expect. For example, the Blue Jays have hit better than any other team in the majors; they crush the ball with runners on, but they also do so with the bases unoccupied. The Twins, suffice to say, do not hit very well overall, ranking 21st in wRC+. They've just managed to become a competent team in key situations, which, like everything else about Minnesota in 2015, is uncommon.
Baseball-Reference offers a statistic called sOPS+, which measures how well a team does in a specific split. The Twins possess an 88 sOPS+ with the bases empty, along with a mark of 108 with runners on. According to the Play Index, six other teams have done ten percent worse than average in the former and five percent better than average in the latter:
|Bases Empty||Runners On|
(Again, those crazy 2013 Cardinals.) Very few teams have stepped up with runners on to the extent that the Twins have.
Let's go back to Minnesota's different offensive splits. Once men have reached base, the Twins have struck out less often, but not to a statistically significant degree (the MLB strikeout rate there falls from 21.1 percent to 19.3 percent). Their walk rate and ISO have remained pretty stable as well, regardless of the scenario. The difference has come with hits on balls in play, where they've ratcheted their production up from .269 to .328. That 50-point differential — which, make no mistake, explains almost all of the 60 runs the Twins have stumbled upon — doesn't appear in too many years:
|Bases Empty||Runners On|
Shockingly, the 2013 Cardinals top the list here as well. In a somewhat distant second place, we see the Twins, trailed closely by the Blue Jays (who, recall, have a pretty decent offense in any situation).
This split perhaps best epitomizes the 2015 Twins. They've made worse contact with runners on base — their soft-hit rate has increased from 17.8 percent to 19.1 percent, while their hard-hit rate has dipped from 29.7 to 26.5 percent — and yet, somehow, they've scrapped out enough hits to gain sixty runs more than a normal team would. They shouldn't have done it, but somehow they have.
The Twins entered the 2015 season without much hope for the playoffs. Whatever happens over the final few games of the season, they can certainly say that they've exceeded expectations for the year; the degree of that, though, would probably surprise them. Still, results are the only thing that matter. Sixty runs translates to six wins, and if one of those can take Minnesota to October, they won't complain.
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All data as of Thursday, October 1st.