Do Teams Get Dragged Down by Jet Lag?
This article was originally published on WahooBlues.com.
No one likes to travel. Vacations are great and changes of scenery can be nice, but that doesn’t make the cramped bus trip or the bumpy plane ride any more pleasant. The destination may be worth it, but when was the last time you stood up after an hours-long voyage with your good mood still fully intact?
This sentiment is shared even by multimillionaires who make their livings playing a children game and are cheered by thousands of adoring fans every time they go to the office. In baseball, “getaway day” is dreaded, and while jet lag alone wouldn’t make the Indians fall to the White Sox (who’d’ve thought that would be a good example this year?), a team that just got in after a long flight is seen as being at a real, if relatively small, disadvantage at the start of a series.
It makes sense that the visiting team wouldn’t look its sharpest after a long flight, especially if time-zone changes are involved. But is it actually true? I compiled a list of every away game the Cleveland Indians played in 2009 and 2010—a full season’s worth of games—along with how many runs they scored and allowed; how far their destination city was from Cleveland; and how many time zones they crossed en route (I tested only away games to eliminate the sample bias of home-field advantage).
I then ran the correlations between the game-based variables (wins, runs scored, and runs allowed) and the geographic ones (miles travelled and time zones crossed). If jet lag plays a major factor in teams’ performances, we would expect the correlations to be negative.
The correlations for all six combinations were very small, but the most surprising part was that the Indians actually played better the farther they travelled. The correlation between wins and distance travelled was .029, while wins and time zones crossed had a correlation of .093.
Of course, correlation does not imply causation, and even if it did, the relationships are too weak to be significant—wins/time zones had an R2 score of .009, while wins/miles came out at just .001. The effect on offense was even smaller: both the runs scored/miles and runs scored/time zone R2 scores round to 0.000. Still, the evidence contradicts the idea that jet lag makes an impact of any significance.
There is a problem with these numbers, though: that they treat all games as the same. Players presumably wouldn’t be as jetlagged in the third or fourth game of an away series as they were in the opener. So I decided to repeat the test, but to include only the first games of road series. The results were quite different (a word of caution: the sample size for series openers is only 52 games).
The correlations between game one wins and distance and time zones travelled were stronger than the previous numbers, and they went the other way. The wins/miles correlation came out at -.113, while wins/time zones had a correlation of -.105—good for R2 scores of .013 and .011, respectively.
The Tribe’s hitting suffered an even bigger regression in these series openers, with a runs scored/miles correlation of -.164 (R2 = .027) and a runs scored/time zones correlation of -.135 (R2 = .018). All these numbers are still too small to draw any firm conclusions, but it may suggest that there is a real (albeit small) jet lag effect on teams at the beginnings of road trips.
But the most interesting aspect of all this is pitching. The correlation between runs allowed and distance and time zones for game ones is also negative, meaning the Indians’ game one pitching and defense was actually better when the team travelled farther. The numbers too are too small to be significant—runs allowed/miles has an R2 of .011, while runs allowed/time zones has an R2 of .013—but the R2 scores are virtually identical to those of the series opener correlations between distance and wins.
The idea that jetlagged teams perform worse is appealing, but it doesn’t seem to hold up against this data. What little negative impact the team as a whole suffers is roughly equal to the benefit enjoyed by pitchers after long flights—which, of course, doesn’t make any sense. We can infer, then, that the effects of travel are insignificant.
There is something of a sample bias here, with good teams like New York (402 miles from Cleveland) and Boston (547) nearby, but I think the talent is spread out enough that the difference would be negligible. Texas (1,043), Tampa (953), and Anaheim (2,037) were pretty good too, while weak Pittsburgh (112) and Baltimore (304) aren’t too far away.
A much larger sample size would be needed to determine whether the minor impact travel seems to make here is real or random chance, but the overall result is clear: while the effects of long flights may vary slightly as the series wears on and different players could be affected differently than others, the evidence here strongly contradicts the idea that jet lag is a substantial detriment to an away team.
Lewie Pollis is a sophomore at Brown University. For more of his work, go to WahooBlues.com. He can be reached at LewsOnFirst@gmail.com. Follow him on Twitter: @LewsOnFirst or @WahooBlues.
there was a paper on this published in Nature (top peer reviewed journal, so should be very scientifically sound) in 2002. II haven’t read it recently, but IIRC according to their analysis, Jet Lag effects were enough to account for 1-2 wins, and helped the Braves to the post season a couple of times in close races. Problem should be solved now, though, as they looked pre-realignment of divisions
link is here:
http://www.nature.com/nature/journal/v377/n6550/abs/377583a0.html
What a terrible article. The data is insignificant, but you claim we can “clearly infer” something from it?
@Bobby: It’s too small of a sample size to tell whether the small effects measured here are real, but we have enough data to conclude that jet lag doesn’t make much of a difference.
The correct way to handle a negative measurement is to put an upper bound on the thing you are measuring: “It looks like x is zero. I can’t say x is zero for sure, but I can be pretty confident x is less than. . .”
95% confidence level is the traditional place to put the boundary. Note that this automatically handles any sample-size issues.
Cogent analysis, although I have to wonder if maybe it would be more illuminating to examine coast-to-coast travel (since, presumably, travel through multiple time zones would magnify the effects of jet lag). I’d be interested to see a report on how the Angels do in G1s at Fenway, the Trop, and Yankee Stadium relative to their average home games, for instance.
There are several issues that I see with this analysis, the biggest of which is that you say you used “how far their destination city was from Cleveland” as a measure. While this makes sense for a road series following a home series, it is not appropriate for a road series that follows a road series.
For example, Cleveland being 1,000 miles from Arlington is of little importance if the Indians had flown out to play the Rangers after a series in Anaheim. This either needed to be properly accounted for (perhaps it actually is, but your explanation suggests otherwise) by calculating the distances between the city of origin and the destination city, or by reducing the sample to only consider the first game of the first road series after a home series (this is certainly the less preferred approach since by my calculations, doing so reduces your sample to only around 20 events for the 2009-2010 seasons).
Secondly, this study doesn’t seem to take into account off days before a series begins. The MLB does a good job of giving teams off days before the start of a road trip as much as possible. If, as your study suggests, the effects of travel on the road team are inconsequential after the first day, accounting for days off in the schedule is vital.
In addition, this study seems to treat all home teams as equal – your study assumes the the home team is always equally (well) rested, when in reality the home team that Cleveland is facing will often have traveled immediately before the first game of a series. Thus to assume that the home team is not suffering from jet lag or a travel hangover is erroneous. In fact, the home team has often just finished a road trip that might have them traveling a greater distance than Cleveland before the first game of the series. It would seem to me that the proper approach would be to calculate the net travel difference that Cleveland experienced compared to the home team
A final point to consider is whether the relationship between distance traveled and fatigue is really linear? In other words, is the fatigue increase when increasing travel from 100 miles to 200 miles the same as the fatigue increase felt increasing travel from 1,200 miles to 1,300 miles? I’m inclined to think that the longer the trip, the smaller the unit increase in fatigue that is produced by each additional mile traveled, but this is just a guess on my part. Nevertheless, the assumption that seems to underlie this study is that the fatigue effect would be linear, and I’m not certain that has been well-founded.
I actually enjoy traveling almost as much as I enjoy the actual vacation part. (anecdata!)
You could easily get a larger sample size by analyzing more teams. I’d be interested to see the results.
This is a really interesting idea for a study, but I agree with much of what James said. Further, doesn’t a study like this have to take ballpark into account? For example, think of a team like the Rockies – they have to make multiple trips to San Francisco and San Diego’s extreme pitcher-friendly parks both just one time zone away.
Further, these players are road warriors. They do this for a living and even when on a home stand are often not in the city where they actually live and call home. My hunch is that when they’re on a plane for a couple hours or more, it’s very appreciated nap time for them rather than what they might consider an inconvenience. I think the much much greater issue is the *amount of time* between one game ending and the next day’s game beginning. I suspect that a team finishing a day game on a thursday, then flying for awhile for their Friday night game – probably 24+ hours between games is going to be in a better state than a home team finishing their extra inning marathon wed. night game and having a 12:30 start the next day. That would be true for both teams participating of course, but would still be measurable based on run production/prevention.
Lastly – just some trivia – Nate Silver did a wonderful analysis of travel distance as it pertains to performance in the NCAA men’s basketball tournament, which could make for some food for thought for how we might tackle this: http://fivethirtyeight.blogs.nytimes.com/2011/03/11/in-tournament-theres-no-place-like-close-to-home/
Thanks for the thought provoking article (and go Tribe!).
If I may add, I’ve always heard that traveling east has a much less dramatic effect. I think that this study could use a check of distance for teams traveling west to account for all of the disastrous road trips that the Reds and other Eastern Time Zone teams have when playing the Dodgers, Padres, and Giants as opposed to hosting them.
Traveling east should have a greater effect, not lesser.
Example: Team One leaves at 1:00 AM EST after the game. They fly 4 hours west and arrive at 2:00 AM PST. They get a good nights rest for the evening game and have a partial day free.
Team Two leaves at 1:00 AM PST after the game. They fly 4 hours east and arrive at 8:00 AM EST. They sleep uncomfortably in the plane for a few hours, get on a bus for the hotel, and settle in for a couple of hours nap before the game.
A bit oversimplified but I think the math is right.
Isn’t it also common for teams to send their pitcher a day early to start a series in order to get him proper rest?
Oh, I thought the headline was going to say “Do Teams Get Dragged Down by Jesus?”. Sorry.
Major League gave us all the Jesus/wins research we need. You see, Jesus, he no help with curveball.
Considering how teams nearly coddle their players (in the sense that their health is a premium), it would seem trivial how much time (or sleep) they lose in traveling. But considering how scheduling is made so that travel is placed at both a premium (in terms of trip and swings) and at a minimum (spending the least amount of time at opposing team locales) I think that travel was probably more debilitating and time consuming when it was done on train. That’s not to detract from the fact that players travel more then before to more location as well. I guess this argument could fall both ways if you consider it carefully enough.
How much can be attibuted to jet lag and how much is hangover? 25 guys on a flight for 3 hours? There might be some drinking going on. Just sayin…