Wednesday, February 1, 2012

Changing Schedules

We place an emphasis on strength of schedule around these parts, with the weekly rankings constituting a blend of a team's own ability along with their opponents. At this point in the season everyone has played each other once but you can get a significant differences in future strength of schedule based on where those games have been played (ie are your remaining tough games at home/away, did you already play the 'big teams' twice?)

The below tables show the average goals per game of a team's opponents to date (Avg) and the average goals per game of a team's next 8 opponents (Next 8). On the defensive side we hope to see a negative difference (ie easier games are to come) while offensively we want to see a positive number.

I wouldn't get carried away with these numbers as we already account for strength of schedule in the weekly rankings, but for some teams it could help explain their offensive or defensive struggles and signify an improvement in the future.

The data can be somewhat misleading in that Man City may well be ranked at the bottom precisely because they haven't played their future opponents twice yet (and likely put a couple past them) but hopefully there is something to learn here (though it's too late for me to draw many conclusions right now).


Ayoob said...

Chris, great stuff. But I didnt understand your comment on why data can be misleading in Man City's case?? Can you elaborate please?

wndrslice said...

i could be wrong, but i think you have the colors backwards. don't you want a positive difference on defense and a negative difference on offense? if not can you please explain further.

TD Ocho said...

I believe he's saying that City put lots of goals past many opponents. Therefore, the teams that they have played twice will have have inflated goals-allowed numbers. Meanwhile, the teams that they have only played once will not have allowed as many goals simply by virtue of not having played against Man City.

Kalix said...

@ TD Ocho
well explained! Must confess I didn't understand chris's meaning either. but now that i do it's a great and very interesting point Chris!

@ wndrslice
For Defence u want a smaller number. I think you need to think about it again.

For Wigan:
Avg goals conceded so far = 1.47, Projected Avg for next 8wks = 1.29

A smaller number here is better (less goals let in!);
smaller = lower = negative difference.
(1.29 is "1.47 minus 0.18")
The "negative 0.18" is a good value. indicating Wigan should let in less goals in the future.

The opposite for the Attack stats

Chris Glover said...

Ayoob - TD is right, but I didn't explain my point very well (it was 1am and I was rambling). I just meant that the reason City's future opponents may look slightly tougher is because they haven't had the misfortune of playing City twice yet (who are averaging almost three goals a game. It wouldn't make a huge difference individually but it might be part of the reason City rank last in attacking difference.

wndrslice - defensively you want your future opponents to have scored less than your opponents to date, hence Wigan are atop with green. The opposite is true with forwards. Again, I probably didn't explain this too well.

Kalix - the data shows the strength of a team's opponents, rather than their own defensive data. So, Wigan's opponents to date have averaged 1.47 goals per game where as the next 8 are only averaging 1.29, therefore the WIgan defense should get a little better.

niloc said...

Hi Chris, love the analysis.
i see you look at some reader's wildcard teams.

would you be willing to look at mine?
and where do i send them to then?


Tony S said...
This comment has been removed by the author.
Tony S said...

Hi Chris,
I'm normally a big fan of your posts but I just can't give much credence to a table that has Wigan top of the defensive table and City bottom of the attacking table. Not to mention the top 5 in the attacking chart looks like a 'who's who' of the relegation battle. There must be something fundamentally wrong with how we are interpreting the data.
The 2 tables do not indicate if a team is due a good run defensively or offensively, all it indicates is their potential for improvement. But this might mean that Wigan will improve from letting in an average of 3 goals per game to only 2 goals per game. But what do we gain from this information? They are still not a good defensive option. Equally, if Man City go from scoring an average of 4 goals a game to an average of 3 goals per game should they be on the bottom of the attacking table? Are they no longer a good attacking option?
This is why the relegated sides are all on top of the attacking charts, they can only improve.
I think the following process would be more informative of a teams attacking and defensive potential for the remainder of the season.
Defensively: The average number of goals a team has been conceding per game so far this season added to the average number of goals their REMAINING opponents have been scoring per game. If the sum of these is low then that team has a good chance of getting clean sheets for the rest of the season.
Attacking: The average number of goals a team has scored per game added to the average number of goals that their remaining opponents have been conceding. If this value is high then that team has good attacking potential for the rest of the season. (This can of course can be amended for the next 8 opponents’ data).
What do you think Chris? I wonder if it would reverse the positions of City and Wigan in the charts?