September Studs: Mining K-BB Differential for 2020 Sleepers

October 15, 2019 By Paul Mammino
Sometimes simpler is better. Paul Mammino looks at September K-BB breakouts to find pitching sleepers for 2020 fantasy baseball.

K-BB is a simple stat but telling. Paul Mammino looks back at the last month of baseball to see if there are any breakouts we need to keep in mind as we start preparing for 2020 fantasy baseball.


Now that the book is officially closed on the 2019 fantasy baseball season, attention begins to turn to 2020. Drafts are starting, with Best Balls opening up here on Fantrax, and analysts are beginning to comb the stats to find that hot sleeper. For the next few weeks, I will be taking a look at September numbers and comparing them to their Rest of Season results to see if there were some major changes or if we can identify any new sleepers/players to avoid. The biggest thing to note is that with these numbers, September is no different than any other 30 day stretch throughout the season and major changes may not have actually taken place. Typically, I will offer some quick notes and thoughts on each name that appears and will dive a little deeper into the guys that I find most interesting.

For the first week, I will be looking at K-BB changers. K-BB is one of my favorite stats and it is extremely simple to understand but carries significant value in player evaluation. In order to be on my list, a pitcher needed 10 September innings and fifty innings prior in the season. Below are the pitchers who saw the greatest improvement in the rates over the season’s final month. I will be discussing the decliners in a separate article.


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September K-BB Differential

PitcherK-BB Diff
Drew Pomeranz33%
Chad Green24%
Yu Darvish22%
Chris Bassitt19%
Jake Odorizzi17%
Shaun Anderson16%
Hansel Robles16%
Raisel Iglesias16%
Michael Pineda15%
Alex Colome15%
Julio Urias13%
Chris Paddack13%
Tyler Chatwood13%
Josh James13%
Gerrit Cole12%
Ross Stripling12%
Eduardo Rodriguez12%
Diego Castillo11%
Joe Musgrove11%

Unfortunately for us, this list is littered with a number of relievers and several of them are not in their team’s closer role. However, these pitchers could still have relevance to fantasy owners.

After being traded to the Brewers, Pomeranz may have found a new home as a high leverage reliever. He was utterly dominant down the stretch after struggling mightily through the beginning of his season. The lefty could be a valuable multi-inning relief piece who racks up a ton of strikeouts.

Chad Green was drafted by many in the exact role I was discussing Pomeranz is best suited for but his early-season numbers were awful. The usually dominant reliever had control issues combined with a homer problem and was demoted to AAA. He eventually made his way back and the strength of his finish has moved him back into a prominent role in Aaron Boone’s pen. He may have some fantasy relevance next season combining good ratios with a strong strikeout rate.

Another reliever to watch is the Giants Shaun Anderson. Late in the season, Anderson was working out of the pen despite receiving some starts early in the year. He found some success combining a high K rate with a slightly elevated walk rate. He converted a few saves while Will Smith recovered from injury and could have some success in a closing role. While the ERA estimators liked the performance the actual ERA did not follow. He could be an interesting deep league name for 2020 if Smith leaves town.

More K-BB Quick Hits

Hansel Robles, Raisel Iglesias, and Alex Colome all closed for their teams and for the most part should remain in the role in 2020 with the possible exception of Robles. While he performed well, the Angels could find a replacement for him in-house or could look to make a free-agent addition. Ty Buttrey is likely still the best arm in that bullpen. Diego Castillo is not the closer but should end up with a handful of saves in a crowded Rays pen. He has some solid value in holds leagues.

The potential roles of Julio Urias, Ross Stripling, and Josh James for 2020 will be an extremely important topic for owners to track. James was slated to be the Astros fifth starter before a Spring Training injury set him back and he was never able to take the role. His incredible stuff combined with the Astros powerful lineup could make him a great post-hype buy this offseason. Urias and Stripling fall into a similar category. They could be extremely valuable fantasy pieces if starting for the Dodgers but the depth within that organization makes it hard to predict. I prefer taking my chances with the upside of Urias but Stripling is criminally underrated and once again will be a guy I am buying into later in drafts.

Starting to Get Somewhere

Now getting to the more interesting names, Yu Darvish was easily one of the best pitchers in baseball for the last few months of the season. From July 1 on, Darvish had the seventh-best FIP among qualified starters and the second-best xFIP behind only Gerrit Cole. He found his control again and was dominant down the stretch. This is the Darvish we once fell in love with and consistently took early in drafts. He is easily one of my favorite pitchers for 2020 and those who only look at the full season line will fail to see the full picture.

The name that surprised me the most of this list was Chris Bassitt. After a quick look, I found a few potentially interesting trends. In September, he saw a massive jump in his K-rate and it led to a massive jump in his K-BB%. Looking at his pitch usage from Brooks Baseball, it appears he started to throw fewer sinkers and more four-seam fastballs. For his career, he has generated whiffs on 12% of his four-seamers as opposed to 6.4% on his sinker. If this change is, in fact, something he plans to maintain or even steer into more for 2020, he could be a cheap source of strikeouts. He was certainly one guy I was not interested in until I looked at this list and then dove deeper into the results.

Jake Odorizzi and Michael Pineda were teammates for the Twins and were a huge part of why they were able to win the Central this season. Odorizzi had a breakout season and it appears he was even stronger toward the end of the season. He is not someone I planned to invest heavily in but if the price is right I will buy again. Pineda’s full-season numbers do not paint the picture of the big righty. He struggled early, was injured and then returned to dominate down the stretch. Unfortunately, he was suspended for PEDS and will miss some of the early season. He is a good guy to stash in a deep league or to be keeping an eye out for on your league’s waiver wire.

There is not much more to say about Paddack outside of the fact that he is a budding ace. He finished the season strong and is well worth the investment for fantasy purposes. The dude is going to be an ace for a very long time. Do not over-think it.

Every year it seems like there is a reason to be excited about Tyler Chatwood and the finish to his season seems to support that yet again this year. I refuse to fall for it again and despite these strong numbers will not have any investments in Chatwood for 2020.

Yet another player who saw a rough start tank his full-season numbers, Eduardo Rodriguez was a bright spot for a rough season for the Red Sox. The lefty may have finally turned a corner and become the fantasy asset we have all dreamed on. The profile is still volatile but so is Robbie Ray and we still invest high draft picks in him. I will once again be willing to build a staff that has E-Rod as one of its heavy hitters.

Lastly, we have Joe Musgrove. Musgrove has always been interesting due to his good stuff and fantastic command. However, he has not been able to parlay this upside into actual results. His September was excellent but there were no major changes in his pitch mix. Although several of his pitches including his four-seam, sinker, and slider saw massive jumps in whiff rate in September. So it looks like once again we will have another offseason of Joe Musgrove, Sleeper pick. Here we go again.

The regular season may be finished, but baseball is never over at FantraxHQ. Follow all of our offseason fantasy baseball content and Draft Day 2020 will be here before you know it.


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