tag:blogger.com,1999:blog-38600807.post8921221836933046154..comments2010-10-20T13:48:31.354-04:00Brian Burkenoreply@blogger.comBlogger31125tag:blogger.com,1999:blog-38600807.post-42521532590393258642010-10-20T13:48:31.354-04:002010-10-20T13:48:31.354-04:00I am a professional sports bettor, and also love to read books on evolutionary biology. Needless to say, I really enjoyed this article.<br /><br />Thanks for all you contributions.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-57431451933085891132010-09-29T19:52:43.295-04:002010-09-29T19:52:43.295-04:00Chris, I suspect you made a math error somewhere.Brian Burkehttp://www.blogger.com/profile/12371470711365236987noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-69358363219991231252010-09-29T15:56:17.113-04:002010-09-29T15:56:17.113-04:00Where are you getting the 57% of all NFL home teams win # from? I ran my own analysis from 1993-2007 and found that home teams won less than 51% of their games. Maybe my data set was dirty? Based on those #&#39;s I started to consider homefield advantage a myth (at least in the NFL, as those were the only games I ran the analysis on). Great stuff. Love the articles here. You are a champion.Chris L.noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-73483699192086310692009-12-26T19:42:05.404-05:002009-12-26T19:42:05.404-05:00I think the primary difference is due to the nature and structure of the sports themselves. NBA basketball features dozens and dozens of possessions, and the HCA is very strong. There is a tiny on every play, and it accumulates as the game goes on. By comparison, college basketball games are shorter and feature fewer possessions, and the overall HCA is weaker.<br /><br />Another factor is the degree of randomness in the sport. For example, MLB baseball is very random. (The Royals beat the Yankees 40% of the time. In contrast, the Lions would beat the Saints about 5% of the time.) It takes many more games for the better teams to come out on top in the MLB.Brian Burkehttp://www.blogger.com/profile/12371470711365236987noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-23291308183226622552009-12-26T17:59:38.108-05:002009-12-26T17:59:38.108-05:00How come home field doesn&#39;t seem to matter in other sports as much as basketball and football?mrparkernoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-34719983511970422522009-12-14T15:24:57.429-05:002009-12-14T15:24:57.429-05:00&quot;it&#39;s when both competitors believe they are fighting over their own territory that real bloody battles occur. That&#39;s when lions will maul each other,&quot;<br /><br />That comment is particularly insightful after a college basketball weekend featuring intra-city games involving Cincinnati/Xavier and Villanova/Temple. It&#39;s not hard to see it in another rivalries like Kentucky/Louisville or Alabama/Auburn in football either.<br /><br />I would expect this sort of theory to hold true more strongly in college or high school sports, where a territorial claim would encompass more than just a stadium and often overlaps. In professional sports, that territorial feeling probably ends at the boundary of your home field.<br /><br />Is the HFA more pronounced in college sports? I would expect so for both my reasons, but also because the larger, better schools schedule more home games against weaker opponents.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-64421974796859124382009-12-03T04:38:36.165-05:002009-12-03T04:38:36.165-05:00Travel has been ruled out for the most part as the primary cause of HFA.Brian Burkehttp://www.blogger.com/profile/12371470711365236987noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-65543716396370539922009-12-03T01:45:17.286-05:002009-12-03T01:45:17.286-05:00Swartz&#39;s work showed that HFA is *not* significantly stronger earlier in the series in baseball. This is an important finding, and really puts a dent in the original poster&#39;s thesis that HFA fades as a visiting team&#39;s familiarity increases. It&#39;s pretty clear that baseball HFA is stronger in, say, innings 1-3 of game 2 in a series than it is in innings 7-9 of game 1 in the series.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-76818406200298246252009-12-02T23:21:03.563-05:002009-12-02T23:21:03.563-05:00I like Marver&#39;s thoughts. Time is finite.<br />Travel requires more concerns that the home team does not have to account for. Anyone ever head over to the in-laws for an overnight or six? Yup, I&#39;m always off my game, too. Now, if I did it eight times a season...SALVADOREnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-51955827841236886622009-11-26T02:17:48.770-05:002009-11-26T02:17:48.770-05:00Two other things to consider:<br />- Length/quality of sleep and concentration are related. Lack of familiarity with sleeping environment is related to length/quality of sleep, so there should be a relationship between the lack of familiarity with sleeping environment (road hotel) and subsequent concentration in the following day(s).<br /><br />- The fact that this occurs most in places/against opponents in which the teams are unfamiliar makes the first point more credible, but it also makes me think that perhaps this has to do with reduced preparation time. If you are going to be playing a team in which you aren&#39;t familiar, the loss of perhaps 5 hours of tape-viewing and/or practice time, could certainly be detrimental in game that week.Marverhttp://pigskintelligence.blogspot.comnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-7501839494511202122009-11-09T23:25:54.279-05:002009-11-09T23:25:54.279-05:00This is most fitting in Seattle, where the &quot;Hawks&quot; have a pretty damn good winning percentage, thanks to their home field advantage :PErichttp://www.blogger.com/profile/01622344413494691086noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-84868446096693527782009-10-30T20:22:02.974-04:002009-10-30T20:22:02.974-04:00.570 is interesting for it equates to four wins out of every seven - gosh, what a surprise; to win the WS a team has to win best of seven and there is a very slim chance this can be achieved on home turf, and then only by one of the teams<br /><br />It would be nice to know how this translates across other sports as well<br /><br />A few years&#39; ago I did a rough check on the Premier League in England; approximately 10% of the time the team scoring first went on to lose. I think this has increased but have not yet done a check for 2008-9<br /><br />The key point is territory. Attackers know they cannot win the &quot;property&quot; in the sense that a medieval castle could be captured, so they act as raiders or guerrillas. Conventional military wisdom requires at least a 2:1 advantage; up to 10:1 depending on the defenses<br /><br />So in most cases, unless very comfortable and familiar with the terrain, the raiding team is after what they can get and on balance the expectancy is that the home team will win<br /><br />Look how poor John Elway&#39;s stats were against divisional opponents compared to divisonal rivals particularly earlier in his career<br /><br />Given that the NFL generally thrives on competitive balance and there are rarely ties, four out seven is the minimum the home team should expect long termAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-73910088124368523242009-09-22T20:43:29.913-04:002009-09-22T20:43:29.913-04:00This is all fascinating stuff but when it comes right down to actually playing the game of football perhaps we can tie some things together. <br />Players and coaches in the NFL have always told me that the distinct advantage that the home team has is hearing the snap count and crowd noise. At home, their tackles can hear the snap count and since they know the count can get to the other guy a fraction of a second faster then the defense. When that same team is on the road, their tackles cannot hear the snap count and it allows the defense that split second advantage.<br />Perhaps in the second half there can be two reasons that advantage may disapate. Crowd is growing hoarse, or they have been taken out of the game due to other factors and their team is losing due to turnovers etc.<br />I know that this is a fact since it comes right from the field of battle so to speak. <br />Also with inter-conference games the visiting teams fans are more apt to travel to the away venue due to familiararity and proximity.<br />If you go and look at the the coaching theories of one of the best, Bill Walsh, he was always preaching one thing above all else. &quot;Beat the other guy to the punch&quot;.<br />No V&#39;s and C&#39;s but real X&#39;s and O&#39;s to perhaps tie in?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-80929274808142781312009-09-22T19:21:12.417-04:002009-09-22T19:21:12.417-04:00Could someone explain to me what effect a home team&#39;s crowd BOOING that team could have over home field advantage? It&#39;s got to have negative consequences, right? Even if they want to behave hawkishly, the booing would suggest that they are doing something wrong, right? And then they&#39;d be less inclined to perform hawkishly again? And maybe become something more like a turtle? Or an ostrich? At least a little bit, right?meixlerhttp://www.blogger.com/profile/14849228566059962558noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-12268199025961045112009-09-22T17:22:16.381-04:002009-09-22T17:22:16.381-04:00John Candido wrote: &quot;Games are almost entirely decided in the first two quarters...&quot;<br /><br />What is your definition of &quot;almost entirely&quot;? What percentage of games where the team leading at the end of the the first half actually wind up winning the game? I&#39;ll be it is lower than 95% (which is what I&#39;d define was &quot;almost entirely&quot;.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-75376309623398565232009-09-21T14:41:12.722-04:002009-09-21T14:41:12.722-04:00Great eclectic post. I wanted to share some similarities to my own research that may help address the question a bit further. Games are almost entirely decided in the first two quarters, so the reduction of the effect is most likley due to the fact that the beginning of the game is most important regardless of home or away advantage. You may find it interesting that Edward Thorp and a Computer Science PhD actually built a statistical prediction model based on the variable of away teams enduring the stress of being on the road, staying in hotels and playing in unfamiliar stadiums. It was successful in Vegas. You can read about it in &quot;Fortunes Formula&quot; by William Poundstone or a paper Thorp wrote entitled &quot;The Kelly Criterion in Blackjack, Sports Betting and the Stock Market&quot;. From a psychological perspective, I also believe that it has much to do with a concept called self-efficacy. That would explain the higher impact of HFA on Inter-divisional games as opposed to Intra-divisional ones.John Candidohttp://www.nflfootballstatistic.comnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-72904162265453656352009-09-18T21:42:27.651-04:002009-09-18T21:42:27.651-04:00Tom G wrote: &quot;We know it is stronger earlier in the game (and in baseball, earlier in the series). &quot;<br /><br /><br />Is there a paper, research or article written on baseball teams having a stronger HFA earlier in the series than later?<br /><br />I challenge you to come up with anything meaningful.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-36568067795638239812009-09-15T05:07:11.907-04:002009-09-15T05:07:11.907-04:00I&#39;ve long felt HFA wasn&#39;t to do with the crowd simply because in the amateur level sports I play there is a significant home-field advantage and we have practically no crowds at all (certainly not tens of thousands of angry Steelers fans waving towels).<br /><br />Of course, we have other issues such as travel conditions, the difficulty of getting subs out to away games etc but even when you think about the games when you travel early and with a decent strength squad, it is remarkably tougher playing away.Iannoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-53382715785458698762009-09-15T03:51:11.945-04:002009-09-15T03:51:11.945-04:00Not at all related to this topic but I want to talk about the Bills/Pats game and this is as good a place as any.<br /><br />The announcers are all talking about how smart Belichick was in not going for the onside. I totally disagree. Obviously it worked out for him but sometimes you just get lucky.<br /><br />The reason isn&#39;t entirely obvious. I haven&#39;t heard anybody mention it yet. The reason was that the onside kick came with an extra timeout. There was 2:06 left on the clock. An onside kick would have almost certainly been done in less than 5 seconds after first touch. That meant that even after a failure, Buffalo would have hit 2:00 after their first play from scrimmage. A regular kick was going to go all the way to 2:00. I couldn&#39;t believe it when he ran it out but I did know he couldn&#39;t take an immediate knee. He should have just run around the end zone for 6 seconds. <br /><br />Anyway after a regular kick, NE needed to stop Buffalo without a single first down. If they succeeded, they&#39;d still have to go 70 yards in a minute and a half without any timeouts. <br /><br />After an onside failure, they still need to stop them. Buffalo could then try a 50 yard field goal or pooch punt. If they get the field goal, NE is in the same position as before except they need the 2 pt and they need to win in OT. In other words about 25% of the previous chance...which isn&#39;t big to begin with. If they don&#39;t try the fg (and frankly I don&#39;t think Buf would have tried the fg in that situation) they need to go 90 yards instead of 70 but with an extra timeout. I&#39;m not altogether sure that is that much more difficult.<br /><br />The onside would have worked only 10% of the time. But I guess it comes down to 10% of scoring with plenty of time + 33% of scoring with a minute and a half and a timeout and 90 yards vs 33% of scoring with a minute and a half and 70 yards and no timeouts.<br /><br />The 33% comes from the assumption that Buffalo would get the gameending first down 67% of the time. <br /><br />I&#39;d be curious to see numbers on all these scenarios and how much difference the extra timeout would have made.Jeff Clarkenoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-61889335014017587562009-09-15T03:24:37.144-04:002009-09-15T03:24:37.144-04:00Reminds me of the old Hawk n Dove bar on Capital Hill in DC.<br /><br />I think its an interesting analogy. I don&#39;t really buy it though. In war (or the animal kingdom) somebody risks their life in the invaded country because it directly affects their quality of life. There really are no realistic alternatives to war. People are largely homeless and starving and there is no realistic economy. They fight because they have to. In the invading country, the direct reason is typically much more convoluted and people go to a considerable amount of trouble to avoid fighting for something that doesn&#39;t directly affect them. Its not the same in sports. The reasons why you play are the same at home or on the road. Money and pride. I suppose you could make an argument on the high school or college level that people are more motivated to impress their friends and family at home but I doubt that makes any difference on the pro level. <br /><br />It is an interesting theory though. To be honest, none of the HFA theories makes a lot of sense to me but HFA clearly exists and there must be at least one reason.Jeff Clarkenoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-37880059825933241162009-09-14T08:26:34.566-04:002009-09-14T08:26:34.566-04:00Yes. There&#39;s 2 ways of looking at it. The matrix above shows only the loser paying the cost of the fight, as if the winner were unscathed. If both pay the same cost, then it&#39;s V/2-C. This would halve the number of hawks in the population.Brian Burkehttp://www.blogger.com/profile/12371470711365236987noreply@blogger.comtag:blogger.com,1999:blog-38600807.post-79927613243895668232009-09-14T05:19:17.494-04:002009-09-14T05:19:17.494-04:00Just a small point which doesn&#39;t even affect the thrust of the argument (which is, as usual, excellent): I think you may have the Hawk-Hawk payoff wrong. If won, the payoff is V-C, but surely if lost, the payoff is -C, so the overall expected payoff is (V-C)/2+(-C)/2. As I say, it&#39;s a little pedantic.Neilynoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-24835474612716649952009-09-13T14:44:50.166-04:002009-09-13T14:44:50.166-04:00One problem with coming up with theories, is that, unfortunately, there is very little we know for sure. We know that homefield advantage is very real. We know it is stronger earlier in the game (and in baseball, earlier in the series). Other than that, there doe very much<br /><br />Is it weaker in divisional games because of familiarity or because of travel? In out of conference games isn&#39;t it stronger when the road team has to cross multiple time zones?<br /><br />Heard that it was also stronger on Monday night than Sunday morning/afternoon ... which makes sense based on survival / fighting / aggressiveness. But not sure if that is true or not <br /><br />Also would be interesting to see how much homefield advantage changes based on the strength of the team. When the Patriots were 16-0 and the Lions 0-16, there was obviously no difference in home record compared with road record. But has anyone broken teams up into groups based on their record and see if there were any differences?<br /><br />The survival / aggressive certainly does have merit. But I don&#39;t think it can fully explain the .580 winning percentage. I also wonder why this is one area of study that is based so much around guessing, rather than analyzing date. Especially when the data is so easy to see for anyone who wants to look at itTom Ghttp://vegassports.blogspot.comnoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-36624409764695929562009-09-13T11:42:01.797-04:002009-09-13T11:42:01.797-04:00Have you looked at the effect scoring first has? Obviously scoring first doesn&#39;t guarantee anything but it certainly helps take the crowd out of it if you&#39;re the visitor, and amplifies it if you&#39;re at home. I&#39;m not sure how you&#39;d qualify it though, because there&#39;s only 1 neutral site game a year.Davenoreply@blogger.comtag:blogger.com,1999:blog-38600807.post-55923802804216580262009-09-13T05:34:49.057-04:002009-09-13T05:34:49.057-04:00Just another thought--If the response is highest at the beginning of games and then fades as the game goes on, then perhaps the signal is telling visitors to be reluctant to <i>enter</i> battle. But once the battle has begun, the response becomes muted.Brian Burkehttp://www.blogger.com/profile/12371470711365236987noreply@blogger.com