February 9, 2009

Back-to-Back game statistics.

Mc79hockey had a post about handicapping the playoff race, and one of the indicators was back-to-back games. One poster commented that his analysis showed that back-to-back games resulted in 6% hit to the road team’s chances of winning (45% vs. 39%). I decided to further investigate this research and I looked at 5 season’s worth of data (ties excluded):
- In all games there were 2466 road wins in 5542 games played (44.5%)
- In the 1432 back-to-back road games there were 593 wins (41.4%)
- If you exclude the back-to-back road games you get (45.6%)
- Almost 25% of road games are back-to-back!
- A difference of about 4%

However, there was no discussion in regards to the rare home back-to-back games. For example Columbus has 6 remaining back-to-back games, but 3 of those are at home. What are those chances?
- In all games there were 3076 road wins in 5542 games played (55.5%)
- In the 612 back-to-back road games there were 332 wins (55%)
- If there is a home back-to-back effect it is much smaller

Now on further investigation of the road back-to-back games showed that the teams who are bad perform even worse than the above averages would suggest:
For example, if a team wins about 31% games the above results would suggest that they would win about 22% of the back-to-back games, but the result is probably closer to 18%. Or on the other end if a team would normally wins 70% of their games the average suggests that they would win about 61% of the back-to-back road games when in fact they’ve won about 66% (or essentially no road back-to-back effect). So the better the team is the less they are affected by back-to-back games.

I was too lazy to look at the result of the combined back-to-back games (both home and away teams are playing back-to-back, which is likely a large majority of the home back-to-back games).

Please note: when I say "back-to-back road games" or "back-to-back home games" I am referring to the second game of the set of two games. The first game is not included in the statistics.
Just a quick example:
For example Vancouver played two games one day apart on December 22, 2008 & December 23, 2008. (won first game, lost second). I am only counting and considering the results of the second game on December 23, 2008 (a loss).


Mogen_david said...

Just to clarify. Are these the backend of the back to backs or either game (assuming that a back to back could be road-raod, road-home and home-road). I made the assumption that it was the backend and got called on it when I quoted your numbers.

JavaGeek said...

backend (or to clarify: the 2nd of two back-to-back games)