The Dickey Effect Part II – Wakefield

I recently did a study that has gained some attention around the baseball world. I studied the effect that R.A. Dickey has on pitchers that pitch after him. It can be found here or here. Many have mentioned or asked for a similar study to be done on recent knuckleballer, Tim Wakefield. Good news everyone! I have already done this for next day starters!

I have yet to collect data for relievers after Wakefield, but it is something I should do in the future. Well what are the results for starters? Big surprise, starters saw a similar effect after Wakefield as the starters after Dickey did.

If you have yet to read the Dickey article, I highly recommend that you do. You will see the previous results and the explanation of the process. Tim Wakefield has a much larger sample size to work with than Dickey, and here it is:

Wakefield Starters

Similar to Dickey, pitchers saw a positive effect almost across the board. The main difference with Wakefield is that walks also went up, but not by much. A career 8% reduction in FIP is significant, and with the sample size, probably fairly accurate. This 8% is smaller than the 18% (for starters) and 10% (for relievers) we saw with Dickey. Why is this?

One reason could be sample size differences, Wakefield has more than double the sample size of pitchers after him. Dickey still has almost 500 innings of starters after him though. The main reason for the difference, I believe, is the effectiveness of Dickey vs. Wakefield. Tim Wakefield has a 4.41 career ERA and a 96 career ERA-. Dickey (as a knuckler) has a 3.28 ERA and 85 ERA-. It would not be a stretch to say that the effect for Dickey should be larger since he actually does baffle hitters more himself.

Another thing to note is that the difference in ERA was larger than the difference in FIP for both Wakefield and Dickey. BABIP was positively affected for starters after both pitchers. Maybe they also reduce good contact as well and the effect could even be a little more than FIP suggests.

Using the 8%, Wakefield likely produced 4.75 runs a season or 0.5 WAR with just the effect on next day pitchers. Over his career this probably compounds to 40.5 runs or 4.1 WAR, in the 1111 innings that starters pitched following Wakefield. I have yet to analyze relievers, but there likely would be an effect as well.

These results for Wakefield further cement the findings that Dickey does leave an impression on hitters after they face him and that the Knuckleball has benefits beyond the Knuckler’s in game value.

Maybe Mr. Ohka will see a little more attention in the likes of these studies?

I know most of you enjoyed the GIF in the first article, so I looked for one for Wakefield but could not find one of the quality. Maybe one of you can find one and post in the comments.

RA Dickey and the Knuckleballer Aging Curve
Ranking FA Pitchers by TIPS

Author: Chris Carruthers

Chris has been a baseball (and Jays) fan for 15 years. He has also played since the age of 6, working his way through Little League and Babe Ruth Baseball as a catcher and first baseman. He got interested in sabermetrics after viewing the movie Moneyball. His continuous self-learning in sabermetrics and advanced stats is driven by his engineering background and love for numbers. Chris's go-to website is FanGraphs, where he has had a few previous community submissions. Chris also enjoys music and plays guitar in his sparse spare time from his studies. He also follows hockey and his favourite team, the Calgary Flames. Follow Chris on Twitter @CCBreakingBlue.

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  1. Chris,

    This is very interesting analysis and a novel way to demonstrate the dynamic effect of a starter. But I am curious: have you tested against a “control” (non-knuckleball) pitcher to ensure this is unique to knuckleballers? If a similar effect appears for, e.g., Mark Buerhle there might be some confounding factor getting overlooked.

    Also, it’s important to note Wakefield wasn’t always a starter, but judging from the “aD IP” column you’ve already accounted for this by only looking at the games after a start and not an appearance.

    Post a Reply
    • Yes, I only accounted for when Wakefield was starting. Also I have actually previously looked at Mark Buehrle up until 2012. Mark Buehrle gave pitchers a 0.7% increase (bad) in FIP. This is not even noticeable.

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