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Josh Johnson Heads to Canada

So as you all no doubt know by now, Josh Johnson was part of the trade of fantasy baseball proportions that is expected to be finalized at some point today. It’s time for JJ to start trading in his dollars for loonies and toonies and switch sides when debating whether to blame Canada. Let’s figure out how the move to the American League and now calling the Rogers Centre home will affect Johnson’s performance.

Here are the relevant park factors:

  RHB K LHB K RHB BB LHB BB RHB 1B LHB 1B RHB HR LHB HR RHB Runs LHB Runs
Rogers Centre 99 103 102 91 99 98 118 100 110 101
Marlins Park 101 98 98 105 104 99 84 80 100 101

And now some league average metrics for starting pitchers:

  K/9 BB/9 BABIP HR/FB ERA
AL 7.0 2.9 0.295 12.5% 4.37
NL 7.3 2.8 0.294 11.3% 4.04

Let’s start with strikeouts. Both ballparks are pretty close to neutral, but obviously, American League pitchers post lower strikeout rates than their National League counterparts, mainly due to the presence of the DH in the lineup, rather than the pitcher. So all else equal, we are going to see a drop in Johnson’s strikeout rate.

Moving on to walks, both parks are relatively neutral for right-handed batters. For lefties though, Rogers Centre has really reduced the free pass, while Marlins Park increased them. Since the RHB factors were also on opposite sides of neutral, the LHB factors prob offset and make both parks about the same. There is also little difference between the leagues in walk rate as well, but I would guess the NL usually has a slightly better mark. So, Johnson’s walk rate may rise, but barely.

Rogers Centre was about neutral in allowing singles, which I am using as a proxy factor for BABIP. In Miami, for whatever reason it was a good place for righties to hit singles. Since BABIP marks are the same across leagues, he might gain a slight advantage from the move for his BABIP.

The home run factors, as you probably could have guessed, show the widest divergence. Everyone expected the new Marlins Park to suppress home runs, and it certainly did just that. The Rogers Centre, on the other hand, has a reputation as a great home run park and that 118 RHB factor bears it out. When you combine the park difference with the switch in leagues and the respective HR/FB ratios, you have to be concerned about Johnson’s home run rate jumping. Amazingly, in four full seasons, Johnson has not allowed a HR/FB ratio above 9.0%. It’s a good bet he will set a career high in that metric next season.

The last factor for comparison is overall runs. Given the home run factor, it’s no surprise that Rogers Centre is a great place to hit. What is a surprise though is that despite reducing the long ball, the new Marlins Park was actually neutral for runs scored. When you combine the difference in run environment due to the park and the 0.33 differential in ERA between the two leagues, you quickly realize that this really hampers Johnson’s fantasy value for next season. Given his annual shoulder issues and this year’s drop in velocity and strikeout rate, he will once again be a real wild card and someone I would steer clear of unless he comes cheaply.