Does the crowd make a difference to the D-backs performance?

A pretty good house at Chase for SnakePitFest, and it was a win for Arizona too. But does attendance correlate to team performance?

The first thoughts in this direction came after Saturday night's game, where a crowd of over 37,600 cheered on Barry Enright and the Diamondbacks at Chase, to a 3-1 victory over Ubaldo Jimenez and the Rockies. It reminded me of SnakePitFest v3.2, where a full house enjoyed a walk-off home-run by Chris Young, after which he said, "When you're out there in the field and you hear the screaming fans it definitely makes a difference for us. Pretty much the fans got us the win tonight." Is that the case? Do home teams in general - and Arizona in particular - play better when there are more people in the stands?

After the jump, we'll take a look to see if there's evidence for this.

At first glance, it would appear so. The three best-attended games of the year to date were Opening Day, the first game in the Yankees series, and Gonzo Retirement Night, and all three resulted in Diamondbacks victories. Expanding the parameters a little further, Arizona are 9-6 when there are more than 28,000 people in attendance, which is a pretty good rate, considering the team's record is 30-36 overall at home in 2010. However, if we look at the extreme other end of the spectrum, the Diamondbacks also appear to play well when largely untroubled by attendees - they have gone 8-8 with less than eighteen thousand in the stands.

More analysis is clearly needed. Next step: average attendance at Chase Field this year for losses: 24,661. For wins: 25,888. That suggests a slight tendency for the team to play better in front of more people. However, if you try to correlate runs scored and runs allowed against crowd numbers, you get the complete opposite result. Runs scored has a marginally negative correlation of -0.06 and runs allowed is fractionally positive (+0.09). That means, the Diamondbacks score less and allows more as the crowd goes up, though it's a pretty weak connection. 

One of the things to note is that not all large crowds are created equal. When Luis Gonzalez retired, just about everyone in the park was cheering for the Diamondbacks. On the other hand, while the number in attendance for the game against the Yankees was almost the same, the crowd was much more evenly-split, and any fan-related energy would seem to apply in the appropriate proportion. It also is likely the case that good teams are more likely to draw fans to Chase: while the Diamondbacks may play better, they could well also be facing better opposition. Again, the Yankees provide a good example of this.

But let's expand things: given the somewhat... "relaxed," shall we say, nature of the Phoenix fan, might we find more impact elsewhere, in cities better known for a rabid fanbase? As a measure of increased home performance, we take the winning percentage of a team there and subtract the winning percentage on the road. The difference which results ranges from zero - Tampa Bay have the same record at Tropicana and elsewhere - to .303, for Detroit, who are 43-24 at home and 20-39 on the road. We then match that against the average crowd for that team. The theory would be, a big home crowd should result in an improved home/road differential. Is that what we see?

Here are the results for all thirty major-league teams, through Tuesday night's games:

Tm Hm W-L W% Rd W-L W% Diff Att
ARI 30 36 .455 19 41 .317 .138 24,805
ATL 44 17 .721 29 36 .446 .275 30,407
BAL 27 38 .415 17 44 .279 .137 21,069
BOS 39 25 .609 33 29 .532 .077 37,630
CHC 28 38 .424 25 36 .410 .014 38,453
CHW 36 24 .600 32 33 .492 .108 26,891
CIN 36 26 .581 36 28 .563 .018 25,585
CLE 26 34 .433 24 41 .369 .064 17,726
COL 40 20 .667 25 40 .385 .282 35,206
DET 43 24 .642 20 39 .339 .303 30,803
FLA 31 31 .500 31 31 .500 .000 17,979
HOU 32 33 .492 24 36 .400 .092 28,288
KCR 29 33 .468 24 40 .375 .093 20,383
LAA 33 29 .532 29 36 .446 .086 40,008
LAD 39 27 .591 25 35 .417 .174 44,796
MIL 30 33 .476 29 33 .468 .008 34,746
MIN 40 22 .645 32 32 .500 .145 39,742
NYM 37 22 .627 26 40 .394 .233 33,024
NYY 42 22 .656 36 26 .581 .076 46,429
OAK 38 27 .585 24 35 .407 .178 17,890
PHI 42 24 .636 28 31 .475 .162 44,948
PIT 29 36 .446 13 48 .213 .233 20,185
SDP 37 22 .627 38 27 .585 .043 25,573
SEA 29 32 .475 20 44 .313 .163 27,076
SFG 39 23 .629 32 33 .492 .137 37,350
STL 41 23 .641 27 32 .458 .183 40,977
TBR 39 24 .619 39 24 .619 .000 22,781
TEX 41 23 .641 30 31 .492 .149 29,499
TOR 32 25 .561 33 35 .485 .076 19,664
WSN 31 29 .517 22 44 .333 .183 23,932

The correlation between differential and attendance is 0.140; present, but not huge. It seems to have more effect at the lower end of attendance. Of the bottom 13 teams in attendance, only three - the Pirates, Nationals and A's - have a differential more than ten points better than league average (.128); two are within ten points of it, and eight are 20+ points lower  However, there are exceptions: the Yankees, Angels and Cubs are all  well-attended, with differentials below average. I also correlated % of park capacity against the differential to see if it was better to have a small, full stadium, than a large, half-empty one. However, the correlation there was only 0.046, basically negligible.

Specifically with regard to the Diamondbacks, our home-road differential is marginally above average, despite the lackluster crowds at Chase this year. I thought I'd also crank the wayback machine up, and see what the numbers were for Arizona, for each year in franchise history. Did the crowds that packed the stadium in 1998, lured by the novelty of baseball, lead to an improved home-field advantage for the team? In two word: not much. Here's the same chart as above, done for each season of Diamondbacks history.

Year Hm W-L W% Rd W-L W% Diff Att
1998 34
47
.420
31 50
.383
.037
44,571
1999 52
29
.642
48
33
.593
.049
37,280
2000 47
34
.580
38
43
.469
.111
36,324
2001 48
33 .593
44 37
.543
.049
33,783
2002 55
26
.679
43
38
.531
.148
39,494
2003 45 36
.556 39
42
.481
.074
34,636
2004 29 52
.358 22 59
.272
.086
31,106
2005 36 45
.444
41
40
.506
-.062
25,425
2006 39 42
.481
37
44
.457
.025
25,823
2007 50
31
.617 40
41 .494 .123
28,707
2008 48 33
.593 34
47
.420
.173
30,987
2009 36 45 .444 34
47
.420
.025
26,281
2010 30 36 .455 19 41 .317 .138 24,805

There's pretty much no discernible trend here either. The correlation over the history of the Diamondbacks is 0.173, in line with the overall MLB number this season. Again, the lowest attendances - 2005, 2006 and 2009 - tend to equate in general with the lowest differentials, but there are exceptions, such as this season, where Arizona are performing much better at home [this year's differential is the second-highest in franchise history]. As in the majors overall, while there seems to be a slight connection, you'd be hard pushed to claim much predictive effect.

There is certainly a benefit to playing on your own turf. Over the 1,215 games played last season, the home team won 54.9%, very close to the numbers in the two years prior to that (55.6% and 54.2%). That only works out to about four games over the course of the season, perhaps not as much as you might expect. From what we've seen here, the home crowd - or, at least, their basic number - do not seem to be a significant part of that benefit, probably representing only a fraction of a win in a year. Maybe the silent majority at Chase are right to save their energy!

X
Log In Sign Up

forgot?
Log In Sign Up

Forgot password?

We'll email you a reset link.

If you signed up using a 3rd party account like Facebook or Twitter, please login with it instead.

Forgot password?

Try another email?

Almost done,

By becoming a registered user, you are also agreeing to our Terms and confirming that you have read our Privacy Policy.

Join AZ Snake Pit

You must be a member of AZ Snake Pit to participate.

We have our own Community Guidelines at AZ Snake Pit. You should read them.

Join AZ Snake Pit

You must be a member of AZ Snake Pit to participate.

We have our own Community Guidelines at AZ Snake Pit. You should read them.

Spinner.vc97ec6e

Authenticating

Great!

Choose an available username to complete sign up.

In order to provide our users with a better overall experience, we ask for more information from Facebook when using it to login so that we can learn more about our audience and provide you with the best possible experience. We do not store specific user data and the sharing of it is not required to login with Facebook.

tracking_pixel_9351_tracker