Friday, May 8, 2009

First Game Back After a Long Road Trip III

At the end of January I concluded that there is no effect on the home team if they are playing the first game back after a long road trip. In order to do this I compared the home record of teams overall with their home records in the first game after road trips of three or more games and then with road trips of five or more games. As of November 26th the home team had a points percentage of 63.5% in the first game back after a three-game (or longer) road trip (37 game sample) and a points percentage of 59.4% in all other situations (283 game sample). The sample size was an issue at that time and the results were updated in January. As of January 28th the home team had a points percentage of 64.0% on the first game back after a three-game (or longer) road trip (93 game sample) and a point percentage of 61.4% in all other situations (622 game sample). The gap was narrowing but it was still rather large and the sample size had increased. The evidence seemed pretty conclusive at the time that there was no detrimental effect on the home team returning from a long road trip. If there was any effect at all, it seemed to be positive.

But the final results challenge these thoughts. With all of the regular season games in the books the home team had a points percentage of 61.3% (168 game sample) in games after a road trip of three games or more. The points percentage in all other home games was 61.9% (1016 game sample). The goal differential also dropped in this last part of the season from +0.452 per game on January 28th to +0.298 per game at the end of the season (shootout goals are excluded from all goal differential calculations). This means that in the period between January 29th and the end of the season the overall goal differential was +8 or +0.107 per game (75 game sample). The points percentage for this segment is only 0.580 and given the overall home winning percentage went up this suggests that in the final months of the season there may be some effect on a team when they return from a long trip. Given that road teams also do worse as the season wears on it would seem that the effects of "tiredness" increase as the season goes on. It would be interesting to see if this phenomenon holds true in other seasons as well.

There are very similar results for the longer road trips. When the team returns from a road trip of five games or longer the points percentage was only 59.8% by the end of the season as compared to 63.0% near the end of January. Over the whole season the sample size is only 46 games so it's still difficult to draw any conclusions from this data.

At this point I would like to look at some data from other seasons and perhaps do a month-to-month analysis of the data in order to come to some firmer conclusions. For now, I would hypothesize that the effects of a "tired" road team are felt more acutely toward the end of the season. If this is true, it would probably be smart to frontload your road schedule if possible (as the Oilers did at the start of this season) and avoid long trips at the end of the year. These conclusions are obviously very tentative and will require the examination of other seasons in order to confirm or refute them.

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