:format(webp)/cdn.vox-cdn.com/uploads/chorus_image/image/17438639/143697527.0.jpg)
In this edition of the series, we'll be examining when and how often teams lay down the sacrifice bunt. If you missed the introduction yesterday, you can take a quick glance at it here.
A quick summary for the impatient
Do teams use the sacrifice bunt as much as they used to?
No. Barely.
(Note: this graph includes all batters, including pitchers. Yes, I know, that's deceptive. Stay with me.)
At their modern peak in 1975, we were seeing a .63 sacrifice attempts a game per team, or two every three games. In 2013, that number has fallen to .42 attempts per game. Note, however, that this is not the lowest rate we've seen: in 1984, managers called for the sacrifice even less than they do now, before quickly reverting to previous levels. (edit: I used bunts per game, but you could also use bunts per plate appearance. When I compared the two numbers, they were so similar as to be basically identical.)
That early-eighties era cost me hours of research, because I was certain I had done my calculations wrong. But after triple-checking, they stand: teams just stopped bunting for a while. We'll return to 1984 as our studies go on, and after looking at other factors in following episodes, I'll try to explain this strange little aberration.
"But what about the different leagues?" you may find yourself asking. "Surely you're not going to lump the American League and the National League together, just because you took out pitchers! The AL has 9-hole hitters too!" And I answer warily, fine. There are distinct differences between the AL and NL. But if I showed those now, it would ruin the ending, and even giant research-driven articles need to have some sort of narrative to keep them going. If you insist on ruining the plot for yourself, you can look at them here and here. I'll get to them, I promise.
In the meantime, it's not enough to just count the number of bunts people are laying down. Let's examining the various game states under which these bunts occur.
Leverage
Moneyball is more than a decade old, and Earl Weaver was getting quoted long before that. It's common knowledge that the sacrifice, by trading extra base hits and outs for advanced baserunners, seeks to increase the chance of scoring one run at the cost of chances at a crooked number. So managers throughout baseball must have a better grip on the key moment when it becomes desirable to play for a single run, correct?
Not really. There has been a slight increase in leverage per bunt since 2010, bringing it more in line with pre-1993 numbers. But these numbers alone should give pause, given that they align almost perfectly with the boom of the steroid era, and its impact on offensive numbers. With higher-scoring games, the leverage of a single plate appearance decreases proportionally, meaning that what little movement we see in the graph likely shares a stronger correlation with runs/game than it does with managerial wisdom.
The Inning State
If the average leverage index of the sacrifice bunt isn't changing, we can't hold up much hope for better timing, can we?
This graph provides more evidence for our earlier theory about managerial misuse of the sacrifice. Though they do show some inclination to use the sacrifice more sparingly in the second inning (where, on average, the heavy hitters are more likely to come to the plate), teams were still just as likely to attempt a sacrifice in the first inning as they were in the ninth. In fact, they were more likely to do so in the 2000s, despite the inflated run environment.
It's only been three-fifths of a season so far in 2013, but it appears that the pendulum has finally swung away from early bunting. A full ten percent more attempts this year have come in the later innings. The last time baseball approached this level of sanity was... 1984.
The Run State
If you're playing for one run, you'd want that run to be the difference, right?
This graph represents the score of the game before the bunt is laid down; we'll talk about what happens afterward next time. And although it's not much movement, there is a noticeable shift toward teams employing the sacrifice while behind in the score, and tied, while teams are less likely to use it for insurance runs. This seems counter-intuitive: why would teams be bunting more when they're down multiple runs? This is the trouble with looking for causation when all we have is correlation. The simplest explanation: teams that tend to be behind are more likely to have hitters who can't hit.
The Base State
The popular conception of the sacrifice is in automatic terms: the first batter of the inning reaches on a walk or a can of corn, then the second batter gamely bunts him into scoring position to wait for his chance at another squib hit to score on. Instead, teams are slowly moving away from the man-on-first sacrifice and the version with the runner on second is becoming more common.
The Out State
Since only bunts with zero or one out qualify as being sacrifice attempts, this average also acts as a ration between the two states. Over time, what we find is that More and more bunts have been taking place with an out already on the board, rising from 20% to 30% over the past forty years. And yet neither pitchers nor position players reflect this rise. There's a reason for this.
The Position
I know, the last couple of graphs have been boring. Here's some actual insight.
The clearest single trend in all of sacrifice bunting is the dramatic shift towards pitchers laying down the sacrifice bunt. More than 40% of all sacrifices are made by pitchers now, in comparison to the quarter or so of the seventies. There are other trends as well: shifts in the demographics of first baseman and designated hitters have reduced their odds of sac bunting to negligible levels, and third baseman are getting beefier as well. Instead, there's a slowly growing contingent of pinch-hit sacrifices (noted on the far right of the graph), perhaps admitting that the bunt is something that only certain ballplayers can handle.
This graph represents the greatest progression in managerial thought.
So do teams use the sacrifice bunt as much as they used to?
No. But pitchers do, and then some.
Position players, meanwhile, are bunting almost a third of the time less than they did forty years ago, with the heavy hitters avoiding it nearly altogether. This is why the AL has seen its sacrifice rates descend, while the NL with its purity keeps slapping the ball into the ground. Managers do seem to have caught onto this single point: why have good hitters bunt when you can have bad hitters bunt? It seems to make perfect sense. It's not like pitchers are going to do anything with the bat anyway.
As we'll see in the next couple of chapters, it actually doesn't work out that way.
The Mariners versus the American League
As a postscript, please find attached the data for your Seattle Mariners, aligned next to the American League average. These graphs are somewhat uglier and less fulfilling than those above, because a single team makes for a much smaller sample size and thus much greater variance.
I meant to talk about managers later on, and I will, in more detail. But it's hard to examine the graph above without noticing some pretty significant patterns:
The rest of the Mariners graphs are less conclusive, and this post is already plenty long, so I'm attaching them as links. Peruse.
In general, the Mariners have been a slightly sacrifice-prone ballclub, particularly in the nineties. Beyond that, it's difficult to glean much of a conclusion with the data so far. Perhaps it's a little surprising that the franchise has tended to sacrifice more with the lead than the average AL team, particularly give how uncommon a lead could be in Seattle for its first fifteen years. But distribution by position only really tells us when certain stars played for the club (note the absence of CF bunting in the 90s) and the leverage index only really shows when interleague play got introduced.
Next time, when the conversation turns to how well teams bunt as opposed to how often, the numbers start getting a little more interesting, especially for the M's.
In review:
- Teams are sacrifice bunting a little less than they used to.
- Position players are sacrificing a lot less, particularly power positions.
- Instead, pitchers are doing it more often than before.
- Managers are still prone to using the sacrifice early in games and in low-leverage situations.
- It's like we haven't really learned that much in forty years.
- 2013 might be an indication that things are turning around. Or it might just be noise.
Looking at the results of these numbers, the reader might find him or herself underwhelmed. It seems as though Earl Weaver, Billy Beane, and Juan Pierre have had little effect on how the sacrifice bunt gets used in ballgames. There are really two possible explanations for this, and I leave it to the reader to come to their own conclusion.
The charitable response, and the one we'll consider when we get to game theory, is that things haven't changed because there's no mathematical incentive for them to; both offense and defense have already settled into optimal strategies given their opponents. This doesn't, however, take into account 1984, when the environment changes rather suddenly, and teams are slow to react. Also, as we'll see on Thursday, it doesn't really explain why bunting continues to provide consistent negative returns, year after year.
The more cynical response would be that baseball managers and players have economic incentives to lean toward conservatism: people don't get fired as often for doing the same thing everyone else is doing. Breaking away from conventional wisdom can make a manager the next Joe Maddon; it can also give you the next Maury Wills.