Miami Marlins September call-ups: Examining Brian Flynn's first start

The Miami Marlins saw another young starter debut yesterday when they sent Brian Flynn, the tall rookie left-hander to the mound for the first time in the majors. Flynn was not as effective as Marlins fans would have hoped, given his success in Triple-A this season. Flynn threw just four-plus innings with two strikeouts, three walks, and two home runs allowed.

Given the occasion, I think it is worth it for Fish Stripes to examine the day that was for Flynn and see what good came from the start and where he can improve. We will look at his Pitch F/X data as provided by Brooks Baseball.

The Pitches

These are the classifications that were given by Pitch F/X's algorithm, but they should be adjusted to fit the known reports of Flynn's work. It is a well-known thing that Flynn throws one type of fastball, primarily a four-seam offering, along with a slider as his primary two pitches. He also works with a curveball and a changeup that he can throw to right-handers. Those four pitch types are represented here from today's game.

The fastball was an interesting point of contention. Reader Lark11 had a relevant question.

Brian Flynn

I’m curious what you make of Flynn’s velocity. Scouting reports had his fastball velocity ticking up into the 93-96 range. Today, it seemed like he was sitting 89-91 with a few 88s and 92s mixed in for good measure. Is 89-91 reflective of his true velocity? I would think the adrenaline from his MLB debut would seeing him throwing a tick harder than usual, at least in spurts, but that wasn’t the case. Or, has the season long workload simply tired him out?

What kind of velocity can we expect going forward?

Prior to his work from today, we had heard that Flynn's fastball was sitting 91-93 mph and touching the mid-90's at its best. Today, everything seemed a tick slower than that, as he averaged just around 90-91 mph and only touched 93. You can see that there was an issue with fatigue as Flynn moved further into the game, based on this velocity chart.

via www.brooksbaseball.net

You can see that towards the end of his 81-pitch outing, Flynn was running low on gas. It is difficult to tell whether this was just a first-start jitters problem, an issue regarding workload, or whether he has had problems in the minors like this. The scouting reports said that his velocity has been up this season and past, so I am inclined to believe that some combination of the above led to decreasing velocity. Still, given that he only got through 81 pitches and began struggling to maintain his heat at around pitch 65, it is something to continue observing.

He threw a fastball in 61 percent of his pitches, which is a rate that lies between a pitcher with an effective, full arsenal like Jose Fernandez (58 percent) and one who depends on the fastball for success like Nathan Eovaldi (71 percent). The slider was the next-most used, which was odd considering the preponderance of righties in the Cubs lineup. Only two lefties (Anthony Rizzo and Ryan Sweeney) were in the lineup for the Cubs today. Flynn threw 10 sliders to those lefties and nine more to right-handers.

The Results

There are positive and negative signs in this case. On the one hand, Flynn's fastball was effective enough to get plenty of swings and misses when hitters swung, as an 18.2 percent mark would be acceptable for a relatively flat fastball with that kind of velocity. The bad news is that all of the well-hit balls allowed by Flynn came on those very pitches, as only two other pitches were hit for base hits and only three other pitches total were put in play. The Cubs were able to put Flynn's fastball into play, and a few times that fastball was hit hard.

As for his breaking pitches, it looked as though they were manageable. He was unable to place his sliders in the strike zone for called strikes, but he made up for it in part by getting whiffs on the swings the Cubs offered. The slider still needs to be good enough to get the occasional seeing strike, as the pitch is not yet touted as unhittable and would be at its most effective versus lefties. Only one right-hander missed a slider, and most watched them dip well below the zone.

The curveball and changeup are going to be important offerings for Flynn if he is to continue in a starting role. Hitters were not swinging at the pitch, but he was able to sneak some of them past Cubs righties for strikes. None of those 12 pitches were put into play either, which is a good thing. However, we had too little a sample to determine which of those two offerings may be better.

Early Conclusions

It is obviously too early to make strong conclusions about Flynn, but it is obvious he has areas for work. He needs to find ways to better utilize either his tertiary offerings or his slider versus righties, as the pitch was not effective in that respect. His fastball was the most sampled pitch, and there are definite questions about its ability to maintain velocity. The tertiary pitches may hold some promise, though which one is too hard to tell.

Flynn will get at least three more chances to start with the Marlins replacing Jose Fernandez in the rotation soon, so the Fish and their fans will get a month to evaluate the merits of Brian Flynn. He may still answer some of our questions of today.