Monday, March 25, 2013

The Dickey Effect: Fact or Fiction?

Before I start, I'd just like to say that you should take everything in this article with a grain of salt for a number of reasons, the two biggest ones being the research done was done by an amateur for FanGraphs, not an employed writer, and that the data being presented is a very small sample size. And now that we've gotten that out of the way, let's begin!

On Friday, Graydon Carruthers, a FanGraphs Community writer published an article on the hypothesized "Dickey Effect". This "Dickey Effect" is quite simple actually, but there hasn't been any real studies into it. Common sense would say that a pitcher relieving Robert Allen Dickey would do better than his usual results because the timing of the opposing hitters is adjusted to a knuckleball, rather than normal 90+ MPH pitches. Furthermore, it is also reasonable to assume that the starter pitching the day after Dickey would also see benefit from this. So Carruthers decided to look at both the results of the relief pitchers the day of a Dickey start, and the starter the day after the Dickey start, to see if this "Dickey Effect" isn't a myth, but rather it is actually something the Blue Jays can take advantage of this year. He looked at the following categories: ERA, WHIP, K%, BB%, HR%, BABIP, and FIP. Of course, this study only went back to the 2010 season as that's truly when R.A. became a full time knuckleballer throwing the pitch greater than 80% of the time. These are the weighted results of the study, the first statistic being those of the "day after starter".

ERA: -17.21%
WHIP: -8.10%
K%: -3.38%
BB%: -5.17%
HR%: -32.96%
BABIP: -11.04%
FIP: -13.34%

So, as you can see, there are decreases in every category(which is good, except for K%). Carruthers notes that the significant decrease in HR% means that the opposition is off their timing the day after Dickey, and because of that, they are making worse contact. I wouldn't really call the contact worse, I'd just say isn't hard contact. The drop in BABIP and decrease in K%, combined with that low HR% might show that hitters are just flailing away to try to make contact, whether it be weak or hard. Now, to how many wins this will contribute to the Jays. Take it away, Graydon:

So a starter (like Brandon Morrow) who follows Dickey against the same team can expect to see around a 17.2% reduction in his ERA that game compared to if he was not following Dickey against the same opponent. For example if Morrow had a 3.00 ERA in games not after Dickey he can expect a 2.48 ERA in games after Dickey. 
So if in a full season where Morrow follows Dickey against the same team 66% of the time (games 2 and 3 of a series) in which he normally would have a 3.00 ERA without Dickey ahead of him, he could expect a 2.66 ERA for the season. This seams to be a significant improvement and would equate to a 7.6 run difference (or 0.8 WAR) over 200 innings.
Not much further explanation needs to be done really. Basically, in this small sample of 3 seasons, the data shows that the starter has a significant improvement when they are pitching the day after Dickey, rather than to a different team or after a day off. On to relievers:

ERA: -16.61%
WHIP: 5.38%
K%: 7.50%
BB%: -12.65%
HR%: -8.53%
BABIP: 13.38%
FIP: -10.40%


As expected there was a good effect on the relievers’ ERA, FIP, K%, and BB%, but the WHIP and BABIP were affected negatively. This tells me that the batters were more free swinging after just seeing Dickey (more hits, less walks, more strikeouts). 
So in a season where there are 55 IP after Dickey in games (like in 2012) there would be a 16.6% reduction in runs given up in those 55 innings. If the bullpen’s ERA is 4.20 without Dickey it can be expected to be 3.50 after Dickey. Over 55 IP this difference would save 4.3 runs (or 0.4 WAR).
So the day of the Dickey game, when relievers come in, they tend to do better, expected as well. As Carruthers points out, the WHIP and BABIP being effected negatively means that batters are more free swinging after facing Dickey. This would support our theory that the HR% drops from the hitters just swinging away to try to make any contact. So, we can at least deduce(with a grain of salt of course), that after facing Dickey, hitters are just trying to make contact.

Carruthers finishes by explaining that depending on Morrow's ERA in 2013, the "Dickey Effect" could add between 1.0-1.2 WAR to Morrow's total, and depending on the ERA of the relievers that come in after him, they can provide around an extra 0.4 WAR. Once again, take this ALL with a grain of salt.

Lastly,a couple of months ago, after the Dickey trade, @James_in_to made a spreadsheet showing how relievers fared after knuckleballers pitch. He comes to the conclusion that relievers pitched to a 3.23 ERA when relieving a knuckleballer. I'm not sure what that is like compared to the league average from around the varying times, but it seems better than most, so I'll take it as another sign that relievers do in fact pitch better after R.A Dickey just came out of the ball game.

1 question that remains completely unsolved from the presented data is why the starters the next day saw a decrease in K%, whereas the Dickey Relievers saw an increase in K%. I don't have any good answers, but if you have any, leave a comment.

So, the evidence might not be the most concrete, but until BP or Elias or any stat organizations like one of those really does an investigation into this, we can't really conclude that this is fact. It would be logical to say that hitters aren't the same after facing Dickey, and the small bit of info we have supports that theory. I'll take any advantage we can get this season, and who knows, maybe this additional 1 WAR or so might be the win that put's the Jays over the Rays come September!

Hope you enjoyed, and I'd love to discuss this, so feel free to please comment below.

You can follow me on twitter, @gideonturk. To connect with the site, Follow us on Twitter, and Like us on Facebook.

Ewan Ross contributed to this point.

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