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LakersFan
07-30-2009, 10:10 AM
During this past season, I looked into how adding home ice advantage would change my model for ranking teams. To summarize: there is a home ice advantage in DI women's hockey, but it does little to change the top 8 ranked teams using my model.

I did some more work in preparation for a talk I am giving at the 2009 Joint Statistical Meetings in DC next week, and I wanted to share it and ask for your thoughts.

Using the past 4 seasons of data and looking at just wins, losses, and ties (no game scores), if I assume that HIA (home ice advantage) is the same for every team the estimate of HIA is 0.167. What does this mean in context? If two equal teams are playing, the probability of the home team winning jumps from 41.9% to 48.5%. The probability of a tie is also calculated, so that is why both of these probabilities are less than 50%.

Roughly speaking, if two equal teams played 50 games, a team would win (on average) 21 at a neutral site and 24 if they played at home. Another way to think about it is that playing half of the 34 games in a season at home earns a team 1.1 more wins that if all those games were played at a neutral site.

To investigate things further, I tried to estimate each teams individual home ice advantage. I will skip the details (you can ask if you really want to know), but here are the results for each team, ranked by best home ice advantage, for the last four seasons of games.


Maine 0.4635
Clarkson 0.4603
New Hampshire 0.4587
St. Cloud State 0.4352
Syracuse 0.4319
Connecticut 0.3991
Colgate 0.3950
Harvard 0.3615
Wayne State 0.3588
Providence 0.3434
Boston 0.3434
St. Lawrence 0.3214
Minnesota State 0.3071
Rensselaer 0.2809
Wisconsin 0.2743
Bemidji State 0.2679
Mercyhurst 0.1826
Boston College 0.1524
Yale 0.1244
Ohio State 0.1011
Dartmouth 0.0723
Union 0.0715
UMD 0.0581
Brown 0.0567
Niagara 0.0535
Minnesota 0.0531
North Dakota 0.0091
Northeastern -0.0716
Vermont -0.0889
Robert Morris -0.1460
Quinnipiac -0.1834
Cornell -0.3664
Princeton -0.4101

Putting these number in context:

When Clarkson plays at home vs. neutral site, the probability of a win increases from 41.9% to 60.2% (assuming equal teams), a gain of 3.1 wins per season (on average).

When Princeton plays at home vs. neutral site, the probability of a win DECREASES from 41.9% to 26.9%. In other words, Princeton losses 2.6 wins a year playing a home vs. neutral ice (on average).

Now, you may argue with the magnitude of these individual home ice advantages, but what I am interested in is the rankings.

Clarkson (very northern New York) and Maine (middle of Maine) have campus locations that can lead to long and difficult travel in winter, while UNH has Olympic sized ice. So these three teams being on top make sense.

It is the lowered ranked teams that I have trouble explaining. Quinnipiac moved to a new rink during this time frame, so we can ignore them for the moment. Robert Morris plays off campus, which explains the lack of home ice advantage.

But what about Princeton and Cornell? Why don't they perform well at home? I have ideas, but I would love to hear your thoughts.

Hux
07-30-2009, 09:18 PM
Forget Princeton and Cornell (two middle to lower tier teams) and ponder Minnesota and Minnesota-Duluth (two perennial NCAA top ranked) with the additional advantage of strong home attendance.

puckster
07-30-2009, 11:13 PM
Looking at last four years of data for Princeton and Cornell, do any of the years add more weight than others to the negative estimate? Do any of the four years produce a positive estimate or do you just ignore the year in your model?

Do you need to explain why Princeton and Cornell play better on the road than they do at home? Not really sure why, but I would agree with your model. I think Cornell may have had a coaching change somewhere in there, but that doesn't really explain it. Princeton is a mystery. Maybe all the visiting teams just really enjoy playing there, not really so intimidating of a place. Would be curious what men's estimate is.

Relatively speaking UMD and Minnesota have been both very good teams over the last four years at both home and on the road, and the estimate is still positive, albeit lower than others, but this doesn't really surprise me. They both win equally well on the road as they do at home, except in 05-06 for minnesota , and last year for UMD (a few more road losses those years than home losses)

puckster
07-30-2009, 11:53 PM
year by year:

Cornell
08-09 home 7-7-2 away 5-7-3
07-08 home 5-9-1 away 7-8-0
06-07 home 2-10-1 away 2-13-1
05-06 home 3-11-1 away 6-7-0
overall home 17-37-5 away 20-35-4

Princeton
08-09 home 7-9-1 away 11-2-1
07-08 home 5-6-3 away 9-6-3
06-07 home 8-6-1 away 8-6-2
05-06 home 12-2-1 away 8-5-1
overall home 32-23-6 away 36-19-7

LakersFan
07-31-2009, 10:38 AM
UM's loss to Robert Morris at home in 08/09 hurt their home ice advantage, and UMD has lost a couple of games at home they should have easily one. Since they are WCHA powerhouses and play very few home non-conference games, maybe teams are used to playing at those places and increase their performance levels when playing those two teams on the road.

As for Cornell and Princeton, there may not even be a reason why the seem to play better on the road than at home. Some ideas....

They play in old, large rinks with few fans.

There is a perception (true or false) that the program is overshadowed by a more successful men's program.

As Ivy League schools that historically don't make the NCAA tournament, there is academic pressure at home that doesn't exist on the road.

I have never seen a game at either location, so I was hoping that someone familiar with the programs might have an insight.

Puckster's summary shows that both teams play better on the road. And when you account for opponent quality via the model, the difference is even greater. If I coached at Princeton, I might try playing all my non conference games on the road.

BTW67
07-31-2009, 01:20 PM
I can't explain why the stats are different for Cornell when compared to the other upstate NY teams, but I can share my experience from when I was a player. It was far more than 4 years ago, but I doubt the road trips have changed much...

I felt I played better on the road because the long trips helped me focus on hockey. I could decompress on the bus with my teammates, get a good night's sleep at the hotel, and be ready to play the next day. Back at school, I was more likely to leave my studying for the weekend, go out with friends (no drinking, of course), or get woken up by my housemates.

As for Princeton, I loved playing there. I can't really explain it. Maybe it was because it's such a cool rink. Maybe it was because we usually had good games against Princeton. Or, maybe it was because we'd get psyched up when the Princeton fans tried to heckle us from the balcony. :eek:

ARM
08-01-2009, 02:06 AM
UM's loss to Robert Morris at home in 08/09 hurt their home ice advantage, and UMD has lost a couple of games at home they should have easily [won]. Since they are WCHA powerhouses and play very few home non-conference games, maybe teams are used to playing at those places and increase their performance levels when playing those two teams on the road.Just about every opponent that Minnesota faces has players on its roster that are from the Twin Cities area, so it is a homecoming for them when they play in Minneapolis. But I'd say a bigger factor is that the team's performance on the road doesn't leave a huge margin for improvement at home. In 2008-2009, the Gophers lost one road game. The prior season, it was two.

UMD is also a very strong road team; I think they are the only team that has won two NCAA quarters on the road during that 4-year period. In addition, the Bulldogs tend to be a bit streaky. When they are playing great, they can win anywhere, and when they are struggling, they do so at home as well.

Radar3535
08-02-2009, 09:10 AM
But what about Princeton and Cornell? Why don't they perform well at home? I have ideas, but I would love to hear your thoughts.IMHO I think more team bonding takes place on the road than at home with some schools which may explain the home vs away disparity.

Jersey
08-02-2009, 01:16 PM
Forget Princeton and Cornell (two middle to lower tier teams) and ponder Minnesota and Minnesota-Duluth (two perennial NCAA top ranked) with the additional advantage of strong home attendance.

Forget Princeton and Cornell? Two pretty good teams this year. I find it hypocritical that someone who puts themself out there as an ambassador for womens hockey, would disparage ANY team. The Tigers beat a lot of good teams this year. Is the home attendence disappointing? Absolutely IMHO. Please do not blame either team for that. Have a whoopie pie with that

Radar3535
08-02-2009, 03:59 PM
Forget Princeton and Cornell? Two pretty good teams this year. I find it hypocritical that someone who puts themself out there as an ambassador for womens hockey, would disparage ANY team. The Tigers beat a lot of good teams this year. Is the home attendence disappointing? Absolutely IMHO. Please do not blame either team for that. Have a whoopie pie with thatIs it cumbersome to walk around with that chip on your shoulder all the time?

Hux
08-04-2009, 10:14 AM
Forget Princeton and Cornell? Two pretty good teams this year. I find it hypocritical that someone who puts themself out there as an ambassador for womens hockey, would disparage ANY team. The Tigers beat a lot of good teams this year. Is the home attendence disappointing? Absolutely IMHO. Please do not blame either team for that. Have a whoopie pie with that

Forget, as in "never mind that, take a look at this little gem of a surprise."

I wasn't disparaging any teams, but referring to their overall records in the time frame in question. The point is that two teams with excellent records, and big numbers of fannies in the seats (relative to most programs), had some of the lowest win percentages at home. You would expect that given their level of overall success, that part of it would be attributable to a boost from home ice, including strong fan support.

ARM
08-04-2009, 03:33 PM
The point is that two teams with excellent records, and big numbers of fannies in the seats (relative to most programs), had some of the lowest win percentages at home.They had low differentials between their home and road percentages, not quite the same as low win percentages at home.