Ground-rule doubles

[RealityChuck]

Back in the day, I can't remember seeing a ground rule-double in MLB.

Now, I feel like I'm seeing at least one a month.

Has the number of them increased? Does anyone keep track of this?

[Frayed Knot]

Closer side walls seem to be a trend, that might be upping the number - we saw a few of those kind in NYM games this week.
On the other hand, one would think the switch away from astroturf has reduced the odds of balls hopping the OF fences.

[Edgy MD]

I would speculate that the relative lack of artificial turf has meant that they have decreased, along with the big turf bounces that facilitate them, but perhaps in post-artificial turf era, walls are being built lower. Thinking here of walls in places like Houston and Philadelphia that were seemingly built 12-15' when 8-10' wold have sufficed, but they wanted to keep big-bouncing balls in play.

The closer-outfield-side-wall thing is a great point. I dislike those.

[seawolf17]

I blame the roids.