Rosenthal

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Farewell Friends
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Rosenthal

Post by Farewell Friends »

Let's assume the "Rosenthal as a starter" talk is just talk and he resumes being a reliever.

What percentage of his 2016 do you assign to injury or just typical decline? I can see a case for both. His swinging strike percentage has been dropping steadily since 2013.

2013: 14.8 percent
2014: 12.8 percent
2015: 11.6 percent
2016: 11.3 percent

However, he came strong out the gate in April. He struck out 16 batters in eight innings, walked just three and had a swinging strike percentage of 12 percent. It dipped to 9 percent in May, hovered around 12 percent in June and July, then spiked to 15 percent when he came back in September (SSS and I'm using Baseball-Reference's splits because I couldn't find how to parse out swinging strikes on Fangraphs).

I guess what I'm hoping to learn here is what our level of optimism should be. If Rosenthal's issues were related to fatigue and he's back to his 2015 self, they've got three very good-to-great relievers. But if this is the beginning of a decline phase and he's mediocre, this bullpen is going to be extremely vulnerable in the middle innings -- again. Making it even more imperative that Rosenthal gets right is that they don't have anyone in Memphis knocking on the door, like they did with Rosenthal and Martinez four years ago. They also don't know how Wacha's shoulder will react to a bullpen role.

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JL21
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Re: Rosenthal

Post by JL21 »

I'm guessing it's something else altogether- either approach or vertical/horizontal movement. His swing percentage outside of the strike zone was down last year (5% off his career, and 9% off of his 2013 peak). It also looks like the release speed on his curveball was way down and it got a lot more sink on it. I'm basically just looking at the advanced stuff to see what looks out of place, and those are the big things. Most everything else looks fairly consistent to where he was in 2014-2015. It just so happens that his slider took a huge dive in value in 2016 (it got hit harder), and that could be a result of hitters being able to pick up on the curve and just attack the slider. Or spit on the curve and let it fall for a ball outside the zone.

(mind you, I don't know any of this stuff... I'm just reading the tea leaves on his Fangraphs and Brooks Baseball pages)

My hunch and hope is that they aren't approaching the 'pen in 2017 needing Rosie to be ROSIE!!! You already start with Oh at the back end, you have Cecil for high leverage matchups, and I hope Wacha can be a decent bridge guy. I think he has all the makings for it. Bowman's a crapshoot but a reasonable one for his role. Broxton is... whatever. Siegrist is probably going to implode this year, but I assume that's part of why they placed a premium on getting Cecil.

If Wacha somehow gets a rotation slot, then you've got Reyes as a blowtorch at the back end to help everyone out. And while I don't think he's particularly suited to the role, you can also have Weaver in a break glass in case of emergency situation in Bowman's role if he goes bust.

Here's the other thing... bullpen arms move fast in the minors. Tui is a guy they could use if he can reassert himself. Rowan Wick could come fast, as could Dakota Hudson. There's also a small-ish chance that Alcantra or Junior Fernandez step up and could be viewed as high velocity guys from late July on. I don't really think that's likely re: Alcantra and Fernandez, but it's not totally out of the realm of possibility.

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Fan_In_NY
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Re: Rosenthal

Post by Fan_In_NY »

Farewell Friends wrote:Let's assume the "Rosenthal as a starter" talk is just talk and he resumes being a reliever.

What percentage of his 2016 do you assign to injury or just typical decline? I can see a case for both. His swinging strike percentage has been dropping steadily since 2013.

2013: 14.8 percent
2014: 12.8 percent
2015: 11.6 percent
2016: 11.3 percent

However, he came strong out the gate in April. He struck out 16 batters in eight innings, walked just three and had a swinging strike percentage of 12 percent. It dipped to 9 percent in May, hovered around 12 percent in June and July, then spiked to 15 percent when he came back in September (SSS and I'm using Baseball-Reference's splits because I couldn't find how to parse out swinging strikes on Fangraphs).

I guess what I'm hoping to learn here is what our level of optimism should be. If Rosenthal's issues were related to fatigue and he's back to his 2015 self, they've got three very good-to-great relievers. But if this is the beginning of a decline phase and he's mediocre, this bullpen is going to be extremely vulnerable in the middle innings -- again. Making it even more imperative that Rosenthal gets right is that they don't have anyone in Memphis knocking on the door, like they did with Rosenthal and Martinez four years ago. They also don't know how Wacha's shoulder will react to a bullpen role.
Really interesting post because I think this is one of those things that you hope some of the advance metrics and stats should help clue us in if there is an issue or was it random variation. With Rosenthal you would think it all starts and ends with the fastball. His fastball speed was near identical to the year before si its not like he lost a few ticks off his fastball.

He actually threw his fastball more often for strikes (56.3% vs 51.8% the year before). Contact on fastball's in the zone was near identical to the season before (81.4% vs. 81.1%) but because he was getting the fastball over more there was more contact against him. And honestly I think its normally a good thing when Rosey is throwing strikes. But the real issue is that hitters stopped chasing his fastball. His out of zone swings on fastballs dropped from 28.5% to 23.8%. So he is throwing more pitches in the zone and getting less swings at the pitches out of the zone.

The type of contact they were making off his fastball also changed. in 2015 30.1% of his fastball that were put into play were flyballs and only 5% of them were home runs. In 2016 his flyball rate cratered on fastballs to 14.3%, but 20% of those flyballs were HRs. Infield flyballs which indicate the worst contact also dropped on his fastballs from 27.5% to 10%, thats not a good thing. The flyballs were converted into groundballs (normally not a terrible thing) but the GB rate increased from 36.8% to 50%. Now the terrible infield defense might have been a factor, as would the type of contact. Now I dont see how to get batted ball type (hard/med/soft) by pitch type, but overall Roseys soft % dropped from 21.9% to 12.8% and his hard % increased from 26.4% to 34.9%.

So basically same velocity, less pitches outside the zone being chased, more pitches in the zone which were hit harder and more likely on the ground or out of the stadium and less popouts and soft flyballs. Now I'm not a pitching coach or an analyst but I would think the Cards would point to either not enough movement (but the movement #s look fine) or bad location on his fastball (catching too much of the plate). I'd have to dig deeper to see if he threw too much down the middle and was just much easier to get barreled up vs. hitting the fringes of the zone.

All that said - I have no idea how to fix him, but having him as a weapon in the pen is probably the difference in 3-6 games in the standings just from a production and fatigue standpoint for the pen.

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