There are loud changes in baseball and quiet ones. While the topline news about this season has been the continuing march toward three true outcomes (walks, strikeouts and home runs), there are other ways 2017 has been different than 2016, 2015 and in some cases all seasons before. Are these changes real? Are they permanent?
Sacrifice flies are down
The unsurprising development is that sacrifice bunts continue trending down. This is easy to explain: Teams have almost total control over how many sacrifice bunts they lay down, and as managers and front offices embrace data showing many sacrifice bunts are counterproductive, a number of traditional “sacrifice situations” are now appropriately treated as “get-a-hit situations.” More surprising, though, is that the sacrifice fly, which involves much subtler shades of intent, is being whittled away.
This year, there have been 0.22 sacrifice flies per game. That’s down 12 percent from last year, which was already the lowest rate since 1972. The 2017 rate would be the lowest since 1954, when sac flies were first tracked.
The first question for any early-season developments: Is it just an April thing? Doesn’t seem to be. Since 2010, there have been slightly more sacrifice flies in April than in the other five months.
The second question: Are we focusing on the right detail? If, for instance, far fewer runners are reaching third base with none or one out, then the lack of sac flies would merely be the trees in this forest.
Is there a plausible explanation given what else we know about modern baseball tactics? The answer here is yes. Pitchers are more skilled at striking batters out — though, notably, the K rate in sacrifice situations is not up from last year. Less easily explained is that sacrifices per ball put in play are down, suggesting either that pitchers are inducing weaker contact or more grounders in sac-fly situations; that third-base coaches are less aggressive; that outfielders have better arms; or that we’ve now sliced these numbers so fine that we’ve got small samples.
Which leads to the fourth question: Will this wash out with a bigger sample? We speculate this one will partly — there are only 13 “missing” sacrifice flies compared with last year’s rates — but not all the way.