Good vs. Bad Jakubauskas

On Jakubauskas' first start for the Mariners, April 16, I was smitten with how often he was throwing strikes. Granted, they were not particularly great strikes (he missed only two bats that night), but just nine games into the season I was a bit tired of seeing a pitching staff miss the zone so often.

The joy in watching a pitcher display the sort of pound the zone mentality that our previous front office thought they were getting elsewhere was short lived however as Jakubauskas' next start was fraught with balls. Thus started an almost perfect pattern in which Jakubauskas displayed either great command or no command in alternating starts. It is an interesting split given that you would not expect to see such a binary distribution* on a skill like command. Below are Jakubauskus' eight starts, split up into good and bad starts based on the tRA of the outing. One start, on May 3, was right about average and therefore I did not include it.

Granted, it is a small sample size. I am not making a claim about some key to his success going forward; it is too soon for that. I do find it interesting though. The batted ball profiles for Jakubauskas during good and bad starts are not that divergent. There is an expected increase in line drives allowed, but there are also fewer fly balls and more infield flies. The swinging strike rates are identical and the called strike rates do not show a huge difference either. Look at the difference in number of balls thrown however.

Coupled with the line drive increase in bad starts it has me wondering if or how the two are related. It certainly makes sense that they would be, but I wonder which way the causation flows. Is it the pitcher throwing more balls, getting into hitter’s counts and having to throw more centered fastballs, which the hitter is now sitting on, ergo more line drives? Or is it the hitters teeing off on the pitcher so he responds by trying to pitch further to the edges of the zone, thus resulting in more balls? Alternatively, it could be a combination of both or neither. This is not compelling evidence, nor is it meant to be.

*Once again, perhaps it is due to the small sample of starts so far.