Another look at sleep's effects

Thanks to the brilliance of commenters Ricardo Bortolon and Rob Pettapiece on my last post on the subject of travel and its effects on major-league teams, I was able to find some very interesting academic research on the subject. W. Christopher Winter and a group from the Martha Jefferson Sleep Medicine Center in Charlottesville, Virginia have conducted a couple of studies recently into how travel affects Major League Baseball teams. Their research was published in Sleep, and you might be able to access the original document if your library subscribes to the journal (Queen's apparently doesn't). Still, their abstract and the summary of their results can be found on page 85 of this PDF, and a Scientific American article on the research by Nikhil Swaminathan can be found here.

There are some very interesting points to consider in these studies. The pilot study in 2005 looked at the performance of MLB teams during the 2004 season alone, and found that teams did better when they were more acclimatized to the current time zone (so not having travelled recently). It's based on research suggesting that it takes a normal human one day to adjust to each time zone crossed. Thus, if you travel from Toronto to Vancouver today, you would not be fully acclimatized to the new time zone until Wednesday. I've made that trip plenty of times, and I can testify that there is a good bit of jet lag involved. They also found that teams were more likely to do well going east-to-west, rather than west-to-east. The follow-up study this year was funded by MLB crunched the numbers for the ten seasons from 1997-2006. It also found that teams with a circadian advantage performed better than expected otherwise and that this increase in performance was the most dramatic when there was a three-hour time difference involved. The east-to-west edge wasn't found here, though.

Here's the sample scenario from the Scientific American piece:

"So, let's say the New York Mets have to travel cross-country—and, so, through three time zones—for a four-game series against the Giants in San Francisco. According to the new research, the Mets would have a three-hour disadvantage, or 60 percent chance of losing the first game; their odds of winning would rise from 40 to 48 percent by the second day, and the Giant's advantage—at least the one based on circadian clocks—would dwindle to 51 percent by the third day. If there was a fourth game in the series, the teams would be equal in terms of their body clocks."

There are obviously other factors that enter into this. The quality of the two teams involved, the pitching and lineup matchups on each day and the team's travel arrangements all could affect it (for example, I'm guessing that arriving midday on the day before a game would be less wearying than arriving around 11:30 at night, but those cases would be considered equal by this methodology). This also is a study looking solely at baseball; it could be different for different sports. However, there's a pretty good sample size here and what seems to be pretty good evidence to suggest that crossing multiple time zones frequently can hurt your team. That would support Phil Jackson's thesis that centrally-located sports teams have an advantage over others. Let me know if you spot any more of these kinds of stories on any sport; I'm interested in tracking this issue for a while.

Does travel have an effect on performance?

Henry Abbott of the excellent TrueHoop posted a link to a very interesting Los Angeles Times piece by Mike Bresnahan yesterday, in which Los Angeles Lakers coach Phil Jackson said he didn't think his team could top his record-setting 72-10 campaign with the 1996 Bulls. The reason Jackson cited wasn't the absence of Michael Jordan, or in fact anything on the court. Instead, he suggested that the Lakers' West Coast location and the increased travel required because of this would prevent them from breaking the record.

This isn't the first time a West Coast coach or GM has discussed the impact of travel on their team, but it's the first time I've heard it in the NBA. In Vancouver sports, this is a common theme, and others are picking up on it: Gregg Easterbrook of the always-excellent Tuesday Morning Quarterback has been tracking the miserable failures of West Coast NFL teams on the East Coast this season (they're currently 1-16 in games played in Eastern Time and 1-17 if you include the game played in London). Moreover, the theme took on new life this year thanks to The Globe and Mail's Matthew Sekeres, who wrote in November that new Vancouver Canucks general manager Mike Gillis was bringing in military sleep experts and biorhythm monitors in an attempt to improve his team's road play. I mentioned this to Abbott, and he was nice enough to quote me and send a link here.

Anyway, I figured it would be useful to take a quantitative look at the subject and its impact on the NBA. I'm not the most brilliant with stats, so I figured the easiest way to do this would be to look at the five remaining teams in the Pacific Time Zone (thanks to the demise of the SuperSonics) and their records at home, on the road in their time zone and on the road out of the time zone. I did this just by going through the schedule by team on NBA.com. This is done in the following spreadsheet:



What can we draw from this? Well, it's a very small sample size so far, but it does seem to suggest that there may be an effect. Of the five teams studied, three of them (Golden State, Sacramento and the Lakers) are demonstrably worse on the road when they're playing outside of their time zone. As a whole, the West Coast teams are 15-23 (.394) on the road out of their time zone thus far. I'd theorize that there may be a similar effect for East Coast teams playing out of their time zone. If anyone has an easy way to pull these kind of records without manually looking through all the games or a way to get this information from other leagues, send me an e-mail at andrew_bucholtz [at] hotmail.com; I'd love to try to expand this study.