Performance of A’s versus large crowds – 2011

Edit: The moves came today. Carignan and Cowgill down to Triple A, Ross and Wagner up to the A's! Looks like K-K gets to live another day. - Zonis

Intro:

One thing I’ve heard around Twitter and the A’s universe in general is that the A’s play worse when they play against large crowds. Most commonly, the complaint is that the A’s play worse at the Coliseum on big draw days, but this also applies on the road, as the team invariably plays against larger crowds on the road than at home. I wanted to see if there was anything to this – is there any difference in record in large crowd games (30K+) vs. lower-attended games (<30K)?

I also wanted to see if there was any difference in something that might be affected by large crowds on a performance level. I think we all remember last year’s debacle of an Opening Day, where Trevor Cahill barely made it through 4 innings and the A’s booted around the ball to the tune of 5 errors. So – are errors something that might vary with attendance? In other words, might A’s players be nervous playing in front of a big crowd, especially considering this isn’t something they are used to regularly.

Methods:

I used B-Ref’s Schedule and Results page to come up with a spreadsheet that had the attendance along with the game’s results. I also went through the boxscores of all 2011 games and entered in the A’s errors for that game.

Results:

Using that spreadsheet, I sorted by attendance and did a quick calculation of the team’s winning percentage (wpct) in high and low attended games (30K+ and <30K).

30K+ games
W	19
L	33
wpct	0.36538462

<30K games
W	55
L	55
wpct	0.5

At first glance, this may seem like something. But, take note of some facts:

• Of those 52 games, only 7 were at home.
• The average final 2011 wpct of the teams the A’s played in the 30K+ games was .547
• The A’s road wpct was .383

So, there’s not a whole to glean from there.

But what about the errors – surely there is something there, right? Well, if we assume a normal distribution of errors (129 on the season):

E_30K+	42
E_<30	87
EPG	0.7962
exp_E_30K+	40.4444444
exp_E_<30	85.555

where EPG is errors per game, E_30K+ is errors committed in 30K games, E_<30K is errors in the <30K games, exp_E_30K+ is the expected number of errors in 30K+ games given the EPG, and exp_E_<30 is the expected number of errors in 30K+ games given the EPG.

Nothing. What if we just do home and away though?

E_home	58
E_away	71
EPG	0.7962963
exp_E_home	64.5
exp_E_away	64.5

Discussion/Limitations:

Why that last point is true is unknown and also leads to a major limitation of this short analysis: how the other teams stack up in this scenario. I am limited by my free time, but mostly by the lack of fielding splits. It would be onerous (albeit, not impossible) to do the same thing with all 29 other teams to see if they also enjoy a defensive boost from being at home.

That said, a 13 error difference between home and road errors is likely insignificant. It could also be that there is a familiarity issue with playing in one location for 81 games, just as home teams have historically enjoyed a significant advantage in wpct.

While only having one year of data is a limitation, it should also be noted that the A’s roster turnover is significant. So, it’s unclear if comparing year-over-year would be ideal.

Join dwishinsky for tonight's game thread shortly before 7:05. I met him yesterday -- he's a good guy.