R.A. Dickey and the Dome Effect

After two plus seasons of watching R.A. Dickey pitch for the Toronto Blue Jays, two things have become very apparent; he has the ability to make hitters look silly and he also has a tendency to give up a lot of home runs.

There’s long been this urban legend that the knuckleball somehow “dances” more in a controlled environment like a closed roof stadium rather than an open air ballpark.

Since the Blue Jays have the ability to open and close the Rogers Centre roof at will, that would appear to be a home field advantage for R.A. Dickey. But on most Dickey starts at home during the warmer months, the roof typically remains open.


Pitchers might tend to feel more comfortable in an enclosed dome environment. There are less variables like temperature and wind, and for the most, a closed roof at the Rogers Centre provides that ideal controlled environment.

That’s especially true for a starter like R.A. Dickey who relies predominantly on the knuckleball; a pitch in itself that’s a whirling sphere of variables.

In his first season with the Blue Jays, R.A. Dickey gave up a total of 35 home runs; which currently stands as his career high. Dickey had always been prone to the long ball, but this was especially prevalent pitching in the AL East.

But pitching within the confines of the Rogers Centre proved to be a bit of a learning curve for Dickey as he gave up nearly twice as many home runs at home than he did on the road.

When pitching at the Rogers Centre, close to 70% of his total home runs were on days where the roof was open.

Dickey made a total of 18 starts at home in 2013 – 11 with an open roof and 7 with a closed roof. He gave up 1.45 home runs per game with the roof open and exactly one home run per game with the roof closed.

In 2014, R.A. Dickey came back down to earth a little bit and his home run numbers somewhat stabilized and represented closer to what his career norms were.

But once again, Dickey surrendered over twice as many home runs with the Rogers Centre roof open than when it was closed.

R.A. Dickey started 17 games at home during the 2014 campaign – 9 with an open roof and 8 with a closed roof. In open roof games, Dickey gave up 1.33 home runs per game compared to 0.625 home runs per game with the roof closed.


And while it may be a small sample size, the results from R.A. Dickey’s 2015 season thus far are the exact opposite of the past two seasons. He’s giving up far more home runs with the roof closed than open.

So far, R.A. Dickey has surrendered one home run per game at home with the roof open and 1.2 home runs per game with the roof closed. Again, keep in mind the small sample size thus far.

Compiling all the data from R.A. Dickey’s entire career with the Blue Jays dating back to 2013, nearly 63% of his home runs at home were given up during games in which the roof was open. Only 37% came when the lid was closed.

Taking a look at the bigger picture, R.A. Dickey has made a total of 22 starts with the Blue Jays at the Rogers Centre with the roof open and 20 starts with the roof closed.

Of those 20 starts with the roof open, he’s given up 1.36 home runs per game. Conversely, in 22 starts with the roof closed, Dickey has only surrendered 0.9 home runs per game; a difference of 0.46 between roof open and closed games.

I’m certainly not intelligent enough to deduce exactly why R.A. Dickey gives up more home runs at home with an open roof, but with over two seasons’ worth of data to look at, all we need to know is the ball flies out of the yard when the roof is cracked.


This is the one unique situation where the Blue Jays actually have the ability to control the environment with the ability to close the roof on days where R.A. Dickey is on the mound.

If the Blue Jays want to squeeze every last drop out of R.A. Dickey, then it’s imperative that they start closing the Rogers Centre roof at home. However miniscule the difference may be between open and closed roof games, that 0.46 home runs per game could be enough.

Fans may not like being cooped up under the roof on a gorgeous summer day, but it only seems like a small price to pay so the Blue Jays can deploy their home field advantage with a knuckleballer like R.A. Dickey on the mound.

Image via Peter PowerThe Canadian Press via AP

Ian Hunter

Ian has been writing about the Toronto Blue Jays since 2007. He enjoyed the tail-end of the Roy Halladay era and vividly remembers the Alex Rodriguez "mine" incident. He'll also retell the story of Game 5 of the 2015 ALDS to his kids for the next 20 years.