DRB WC #5: Home Field-ing Advantage

The Rays find themselves in a small minority when it comes to playing at home due to the much discussed use of a dome and artificial grass. In the 2010 season the Rays played well at home putting up and very good 49-32 record under the Tropicana lights. One definition of home field advantage I found is as follows:

(The) Edge the home team is expected to have as a result of the familiarity with the arena and effect of travel on the visting team.

Now, this got me thinking. The Rays had a good defence last year, a 2010 team UZR of 32.8, good for 3rd in the AL and 7th in all of MLB but how did the artificial playing surface affect the Rays defence whilst playing at the Trop?

To look a little bit into this (and this is just touching upon the subject) I decided to use Fangraphs to compare Rays players split UZR ratings, home and on the road. I took a sample of players who took the field for more than 200 innings at one position, obviously not including catchers or pitchers. Unfortunately I didn't have time to filter how many innings each player had at home and on the road so 200 innings is over the season as a whole, small sample size rules may apply! (but forget that for now ;) )

Or a more visually pleasing look.

As you can see there are a few of instances where a player has a better UZR rating on the road than at home. These are Zobrist in RF (albeit 0.2 difference), Upton, Joyce and Kapler. I'm not sure if there is any relevance in the fact that all these players are from the OF but if we look at the overall picture the Rays home team UZR among these players is 28.5, whilst on the road it is 6.5, a 22.0 difference. Now, I'm sure the main reasons for this is the fact that the players know their home field, the way it plays, the bounce, the speed off the surface etc...so I decided to look at the rest of the AL East to get a better idea of how our divisional rivals faired on their home field using the same criteria.

The results were fairly surprising.

From this table you can see that the only team other than the Rays to have a better home UZR rating compared to their road UZR is the Blue Jays, albeit with an awful road rating. Of course, you could say the Rays had an overall better defence, which they do but you would still expect a teams home UZR to far outweigh their road equivalent.

On the face of it, it looks as though the Rays have a rather large home fielding advantage and play better on the artificial surface of the Trop than most of their divisional rivals do on their home fields. It would be interesting to look at how the road team performs on the rays ‘turf' but from what I can see we are gaining from the lack of grass.